deps: update dependency com.google.protobuf:protobuf-bom to v3.12.0 (#6)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [com.google.protobuf:protobuf-bom](https://developers.google.com/protocol-buffers/) ([source](https://github.com/protocolbuffers/protobuf)) | minor | `3.11.4` -> `3.12.0` |

---

### Release Notes

<details>
<summary>protocolbuffers/protobuf</summary>

### [`v3.12.0`](https://github.com/protocolbuffers/protobuf/releases/v3.12.0)

[Compare Source](https://github.com/protocolbuffers/protobuf/compare/v3.11.4...v3.12.0)

### Protocol Compiler

-   [experimental] Singular, non-message typed fields in proto3 now support
    presence tracking. This is enabled by adding the "optional" field label and
    passing the `--experimental_allow_proto3_optional` flag to protoc.
    -   For usage info, see [docs/field_presence.md](docs/field_presence.md).
    -   During this experimental phase, code generators should update to support
        proto3 presence, see [docs/implementing_proto3_presence.md](docs/implementing_proto3_presence.md) for instructions.
-   Allow duplicate symbol names when multiple descriptor sets are passed on
    the command-line, to match the behavior when multiple .proto files are passed.
-   Deterministic `protoc --descriptor_set_out` ([#&#8203;7175](https://github.com/protocolbuffers/protobuf/issues/7175))

### C++

-   [experimental] Added proto3 presence support.
-   New descriptor APIs to support proto3 presence.
-   Fix for [#&#8203;7463](https://github.com/protocolbuffers/protobuf/issues/7463) in -rc1 (core dump mixing optional and singular fields in proto3)
-   Enable Arenas by default on all .proto files.
-   Documented that users are not allowed to subclass Message or MessageLite.
-   Mark generated classes as final; inheriting from protos is strongly discouraged.
-   Add stack overflow protection for text format with unknown fields.
-   Add accessors for map key and value FieldDescriptors.
-   Add FieldMaskUtil::FromFieldNumbers().
-   MessageDifferencer: use ParsePartial() on Any fields so the diff does not
    fail when there are missing required fields.
-   ReflectionOps::Merge(): lookup messages in the right factory, if it can.
-   Added Descriptor::WellKnownTypes enum and Descriptor::well_known_type()
    accessor as an easier way of determining if a message is a Well-Known Type.
-   Optimized RepeatedField::Add() when it is used in a loop.
-   Made proto move/swap more efficient.
-   De-virtualize the GetArena() method in MessageLite.
-   Improves performance of json_stream_parser.cc by factor 1000 ([#&#8203;7230](https://github.com/protocolbuffers/protobuf/issues/7230))
-   bug: [#&#8203;7076](https://github.com/protocolbuffers/protobuf/issues/7076) undefine Windows OUT and OPTIONAL macros ([#&#8203;7087](https://github.com/protocolbuffers/protobuf/issues/7087))
-   Fixed a bug in FieldDescriptor::DebugString() that would erroneously print
    an "optional" label for a field in a oneof.
-   Fix bug in parsing bool extensions that assumed they are always 1 byte.
-   Fix off-by-one error in FieldOptions::ByteSize() when extensions are present.
-   Clarified the comments to show an example of the difference between
    Descriptor::extension and DescriptorPool::FindAllExtensions.
-   Add a compiler option 'code_size' to force optimize_for=code_size on all
    protos where this is possible.

### Java

-   [experimental] Added proto3 presence support.
-   Fix for [#&#8203;7480](https://github.com/protocolbuffers/protobuf/issues/7480) in -rc1 ("TextFormat and JsonFormat ignore experimental proto3 optional enums")
-   Fix for [#&#8203;7505](https://github.com/protocolbuffers/protobuf/issues/7505) in -rc1 (" toString() returns incorrect ascii when there are duplicate keys in a map")
-   Mark java enum \_VALUE constants as [@&#8203;Deprecated](https://github.com/Deprecated) if the enum field is deprecated
-   reduce <clinit> size for enums with allow_alias set to true.
-   Sort map fields alphabetically by the field's key when printing textproto.
-   TextFormat.merge() handles Any as top level type.
-   Throw a descriptive IllegalArgumentException when calling
    getValueDescriptor() on enum special value UNRECOGNIZED instead of
    ArrayIndexOutOfBoundsException.
-   Fixed an issue with JsonFormat.printer() where setting printingEnumsAsInts()
    would override the configuration passed into includingDefaultValueFields().
-   Implement overrides of indexOf() and contains() on primitive lists returned
    for repeated fields to avoid autoboxing the list contents.
-   Add overload to FieldMaskUtil.fromStringList that accepts a descriptor.
-   [bazel] Move Java runtime/toolchains into //java ([#&#8203;7190](https://github.com/protocolbuffers/protobuf/issues/7190))

### Python

-   [experimental] Added proto3 presence support.
-   [experimental] fast import protobuf module, only works with cpp generated code linked in.
-   Truncate 'float' fields to 4 bytes of precision in setters for pure-Python
    implementation (C++ extension was already doing this).
-   Fixed a memory leak in C++ bindings.
-   Added a deprecation warning when code tries to create Descriptor objects
    directly.
-   Fix unintended comparison between bytes and string in descriptor.py.
-   Avoid printing excess digits for float fields in TextFormat.
-   Remove Python 2.5 syntax compatibility from the proto compiler generated \_pb2.py module code.
-   Drop 3.3, 3.4 and use single version docker images for all python tests ([#&#8203;7396](https://github.com/protocolbuffers/protobuf/issues/7396))

### JavaScript

-   Fix js message pivot selection ([#&#8203;6813](https://github.com/protocolbuffers/protobuf/issues/6813))

### PHP

-   Persistent Descriptor Pool ([#&#8203;6899](https://github.com/protocolbuffers/protobuf/issues/6899))
-   Implement lazy loading of php class for proto messages ([#&#8203;6911](https://github.com/protocolbuffers/protobuf/issues/6911))
-   Correct [@&#8203;return](https://github.com/return) in Any.unpack docblock ([#&#8203;7089](https://github.com/protocolbuffers/protobuf/issues/7089))
-   Ignore unknown enum value when ignore_unknown specified ([#&#8203;7455](https://github.com/protocolbuffers/protobuf/issues/7455))

### Ruby

-   [experimental] Implemented proto3 presence for Ruby. ([#&#8203;7406](https://github.com/protocolbuffers/protobuf/issues/7406))
-   Stop building binary gems for ruby &lt;2.5 ([#&#8203;7453](https://github.com/protocolbuffers/protobuf/issues/7453))
-   Fix for wrappers with a zero value ([#&#8203;7195](https://github.com/protocolbuffers/protobuf/issues/7195))
-   Fix for JSON serialization of 0/empty-valued wrapper types ([#&#8203;7198](https://github.com/protocolbuffers/protobuf/issues/7198))
-   Call "Class#new" over rb_class_new_instance in decoding ([#&#8203;7352](https://github.com/protocolbuffers/protobuf/issues/7352))
-   Build extensions for Ruby 2.7 ([#&#8203;7027](https://github.com/protocolbuffers/protobuf/issues/7027))
-   assigning 'nil' to submessage should clear the field. ([#&#8203;7397](https://github.com/protocolbuffers/protobuf/issues/7397))

### C

-   [experimental] Add support for proto3 presence fields in C# ([#&#8203;7382](https://github.com/protocolbuffers/protobuf/issues/7382))
-   Cleanup various bits of Google.Protobuf ([#&#8203;6674](https://github.com/protocolbuffers/protobuf/issues/6674))
-   Fix conformance test failures for Google.Protobuf ([#&#8203;6910](https://github.com/protocolbuffers/protobuf/issues/6910))
-   Fix latest ArgumentException for C# extensions ([#&#8203;6938](https://github.com/protocolbuffers/protobuf/issues/6938))
-   Remove unnecessary branch from ReadTag ([#&#8203;7289](https://github.com/protocolbuffers/protobuf/issues/7289))
-   Enforce recursion depth checking for unknown fields ([#&#8203;7132](https://github.com/protocolbuffers/protobuf/issues/7132))
-   Mark GetOption API as obsolete and expose the "GetOptions()" method
    on descriptors instead ([#&#8203;7491](https://github.com/protocolbuffers/protobuf/issues/7491))
-   Remove Has/Clear members for C# message fields in proto2 ([#&#8203;7429](https://github.com/protocolbuffers/protobuf/issues/7429))

### Objective-C

-   [experimental] ObjC Proto3 optional support ([#&#8203;7421](https://github.com/protocolbuffers/protobuf/issues/7421))
-   Block subclassing of generated classes ([#&#8203;7124](https://github.com/protocolbuffers/protobuf/issues/7124))
-   Use references to Obj C classes instead of names in descriptors. ([#&#8203;7026](https://github.com/protocolbuffers/protobuf/issues/7026))
-   Revisit how the WKTs are bundled with ObjC. ([#&#8203;7173](https://github.com/protocolbuffers/protobuf/issues/7173))

### Other

-   Add a proto_lang_toolchain for javalite ([#&#8203;6882](https://github.com/protocolbuffers/protobuf/issues/6882))
-   [bazel] Update gtest and deprecate //external:{gtest,gtest_main} ([#&#8203;7237](https://github.com/protocolbuffers/protobuf/issues/7237))
-   Add application note for explicit presence tracking. ([#&#8203;7390](https://github.com/protocolbuffers/protobuf/issues/7390))
-   Howto doc for implementing proto3 presence in a code generator. ([#&#8203;7407](https://github.com/protocolbuffers/protobuf/issues/7407))

</details>

---

### Renovate configuration

:date: **Schedule**: At any time (no schedule defined).

:vertical_traffic_light: **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

:recycle: **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

:no_bell: **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#googleapis/java-iam).

pom.xml

@@ -64,7 +64,7 @@
     <github.global.server>github</github.global.server>
     <site.installationModule>google-iam-parent</site.installationModule>
     <google.common-protos.version>1.18.0</google.common-protos.version>
-    <protobuf.version>3.11.4</protobuf.version>
+    <protobuf.version>3.12.0</protobuf.version>
     <junit.version>4.13</junit.version>
     <grpc.version>1.29.0</grpc.version>
     <guava.version>29.0-android</guava.version>