deps: update google-http-client to 1.39.0 (#1957)

Update dependencies to match next shared-dependencies release (0.20.0)

deps: update gax to 1.62.0
deps: update google-common-protos to 2.1.0
deps: update protobuf to 3.15.2

Co-authored-by: Elliotte Rusty Harold <elharo@users.noreply.github.com>
Co-authored-by: Tomo Suzuki <suztomo@google.com>

boms/cloud-oss-bom/pom.xml

@@ -47,13 +47,13 @@
     <guava.version>30.1-android</guava.version>
     <google.cloud.java.version>0.148.0</google.cloud.java.version>
     <io.grpc.version>1.36.0</io.grpc.version>
+    <http.version>1.39.0</http.version>
     <protobuf.version>3.15.3</protobuf.version>
-    <http.version>1.38.1</http.version>
     <!-- We don't use gax-bom because it includes the artifacts with 'testlib' classifier.
         When updating gax.version, update gax.httpjson.version too. -->
-    <gax.version>1.61.0</gax.version>
-    <gax.httpjson.version>0.78.0</gax.httpjson.version>
-    <common.protos.version>2.0.1</common.protos.version>
+    <gax.version>1.62.0</gax.version>
+    <gax.httpjson.version>0.79.0</gax.httpjson.version>
+    <common.protos.version>2.1.0</common.protos.version>
     <iam.protos.version>1.0.9</iam.protos.version>
   </properties>