deps: update dependency io.grpc:grpc-bom to v1.29.0 (#209)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [io.grpc:grpc-bom](https://github.com/grpc/grpc-java) | minor | `1.28.1` -> `1.29.0` |

---

### Release Notes

<details>
<summary>grpc/grpc-java</summary>

### [`v1.29.0`](https://github.com/grpc/grpc-java/releases/v1.29.0)

[Compare Source](https://github.com/grpc/grpc-java/compare/v1.28.1...v1.29.0)

#### Behavioral Changes

-   core, grpclb: change policy selection strategy for Grpclb policy (move logic of querying SRV into Grpclb's own resolver) ([#&#8203;6723](https://github.com/grpc/grpc-java/issues/6723)). System property `io.grpc.internal.DnsNameResolverProvider.enable_grpclb` is eliminated, grpc-grpclb dependency implicitly enables querying SRV records since v1.24.2

#### New Features

-   core: `ServerInterceptors.useInputStreamMessages()` now preserves the `KnownLength` interface when wrapping InputStream ([#&#8203;6852](https://github.com/grpc/grpc-java/issues/6852)). This should prevent certain optimizations from being disabled when using useInputStreamMessages
-   core: `ServerInterceptors.useInputStreamMessages()` and `useMarshalledMessages()` now preserve the SchemaDescriptor, so the methods are now compatible with the reflection service ([#&#8203;6851](https://github.com/grpc/grpc-java/issues/6851))

#### Bug Fixes

-   core: Fix IllegalStateException if remote-specified decompressor is unknown ([#&#8203;6864](https://github.com/grpc/grpc-java/issues/6864))
-   core: keep round_robin lb subchannel in TRANSIENT_FAILURE until becoming READY ([#&#8203;6657](https://github.com/grpc/grpc-java/issues/6657)). This avoids RPC being indefinitely queued when subchannels are bouncing back and forth between CONNECTING and TRANSIENT_FAILURE
-   netty: fixed a bug when grpc-netty and grpc-netty-shaded were both used, which could result in "ClassCastException: io.netty.util.AsciiString cannot be cast to io.grpc.netty.shaded.io.netty.util.AsciiString" ([#&#8203;6765](https://github.com/grpc/grpc-java/issues/6765))
-   netty: Prevent thread interruption during server start from leaking socket ([#&#8203;6867](https://github.com/grpc/grpc-java/issues/6867))
-   okhttp&#x3A; fix incorrect connection-level flow control handling at beginning of connection ([#&#8203;6742](https://github.com/grpc/grpc-java/issues/6742)). This only impacted users of `OkHttpChannelBuilder.flowControlWindow()`, who seem to be few since this bug was not reported sooner
-   core: A Java 9+ ABI compatibility issue with java.nio.ByteBuffer is fixed ([#&#8203;6839](https://github.com/grpc/grpc-java/issues/6839)). This only impacted users manually compiling grpc-java with JDK 9+ and then using it as a library for applications that run with JDK 8- (e.g., on Android). This does not impact the pre-built JARs on Maven Central
-   core: fixed a bug in health check config propagation. ([#&#8203;6804](https://github.com/grpc/grpc-java/issues/6804))
-   benchmarks: some netty benchmarks failed to start and are now fixed ([#&#8203;6877](https://github.com/grpc/grpc-java/issues/6877)). This was a regression introduced in v1.23.0

#### Documentation

-   Add Javadoc for grpc-services and grpc-grpclb to the grpc-all project. This increases the number of classes shown at <https://grpc.io/grpc-java/javadoc/>
-   examples: Add a JWT authentication example ([#&#8203;5915](https://github.com/grpc/grpc-java/issues/5915))

#### Dependencies

-   Bump guava to 28.2-android ([#&#8203;6772](https://github.com/grpc/grpc-java/issues/6772))
-   Bump netty to 4.1.48.Final, bump tcnative to 2.0.30.Final ([#&#8203;6845](https://github.com/grpc/grpc-java/issues/6845))
-   Bump truth version to 1.0.1 ([#&#8203;6754](https://github.com/grpc/grpc-java/issues/6754))

#### Compiling

-   android: add grpc-android into main build ([#&#8203;6793](https://github.com/grpc/grpc-java/issues/6793)). Compiling with `-PskipAndroid=false` (default) includes building grpc-android module, which requires Android SDK

#### Acknowledgements

[@&#8203;chrisschek](https://github.com/chrisschek) 
[@&#8203;elharo](https://github.com/elharo) Elliotte Rusty Harold
[@&#8203;herbyderby](https://github.com/herbyderby) Chris Nokleberg
[@&#8203;markb74](https://github.com/markb74)
[@&#8203;ST-DDT](https://github.com/ST-DDT)

</details>

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pom.xml

@@ -160,7 +160,7 @@
     <google.auth.version>0.20.0</google.auth.version>
     <google.api.version>1.30.9</google.api.version>
     <google.http.version>1.34.2</google.http.version>
-    <grpc.version>1.28.1</grpc.version>
+    <grpc.version>1.29.0</grpc.version>
     <protobuf.version>3.11.4</protobuf.version>
     <opencensus.version>0.24.0</opencensus.version>
     <annotations-api.version>1.3.2</annotations-api.version>