Tracking issue for s2a public APIs

[rmehta19]

[blakeli0]

There were errors in sdk-platform-java's CI

(00:37:16) ERROR: /home/runner/.cache/bazel/_bazel_runner/cf5fb8c2c66b8a944ea6af7c9b248db5/external/maven/BUILD:41:11: 
no such target '@io_grpc_grpc_java//s2a:s2a': target 's2a' not declared in package 's2a' defined by 
/home/runner/.cache/bazel/_bazel_runner/cf5fb8c2c66b8a944ea6af7c9b248db5/external/io_grpc_grpc_java/s2a/BUILD.bazel 
(Tip: use `query "@io_grpc_grpc_java//s2a:*"` to see all the targets in that package) and referenced by '@maven//:com_google_api_gapic_generator_java'

we have to fix it by removing override_targets = IO_GRPC_GRPC_JAVA_OVERRIDE_TARGETS in maven_install. See the commit that fixed it.