Add suppressions for GuardedBy violations

[graememorgan]

This supports releasing a new version of GuardedBy which finds more mistakes than it used to.

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ Graeme Morgan (a05b656, 448d5f1)

[dapengzhang0]

@garrettjonesgoogle There might be more need to suppress

/git/grpc-java/okhttp/src/main/java/io/grpc/okhttp/OkHttpClientTransport.java:433: error: [GuardedBy] This access should be guarded by 'stream.transportState().lock'; instead found: 'this.lock'
    stream.transportState().start(nextStreamId);
                           ^
    (see https://errorprone.info/bugpattern/GuardedBy)
/git/grpc-java/okhttp/src/main/java/io/grpc/okhttp/OkHttpClientTransport.java:1139: error: [GuardedBy] This access should be guarded by 'stream.transportState().lock'; instead found: 'OkHttpClientTransport.this.lock'
          stream.transportState().transportDataReceived(buf, inFinished);
                                 ^
    (see https://errorprone.info/bugpattern/GuardedBy)
/git/grpc-java/okhttp/src/main/java/io/grpc/okhttp/OkHttpClientTransport.java:1189: error: [GuardedBy] This access should be guarded by 'stream.transportState().lock'; instead found: 'OkHttpClientTransport.this.lock'
            stream.transportState().transportHeadersReceived(headerBlock, inFinished);
                                   ^
    (see https://errorprone.info/bugpattern/GuardedBy)
/git/grpc-java/okhttp/src/main/java/io/grpc/okhttp/OkHttpClientStream.java:263: error: [GuardedBy] This access should be guarded by 'OkHttpClientStream.this.state.lock'; instead found: 'this.lock'
      state.onStreamAllocated();
           ^
    (see https://errorprone.info/bugpattern/GuardedBy)
/git/grpc-java/okhttp/src/main/java/io/grpc/okhttp/OkHttpClientStream.java:376: error: [GuardedBy] This access should be guarded by 'this.transport.lock'; instead found: 'this.lock'
        transport.removePendingStream(OkHttpClientStream.this);
                 ^
    (see https://errorprone.info/bugpattern/GuardedBy)
/git/grpc-java/okhttp/src/main/java/io/grpc/okhttp/OkHttpClientStream.java:419: error: [GuardedBy] This access should be guarded by 'this.transport.lock'; instead found: 'this.lock'
      transport.streamReadyToStart(OkHttpClientStream.this);
               ^
    (see https://errorprone.info/bugpattern/GuardedBy)

[graememorgan]

@garrettjonesgoogle There might be more need to suppress

...

You're quite right. Done.

[suztomo]

Note for myself: Once this PR is merged to master, I'll check #6574.

[ejona86]

I've filed #6578 for us to try to clean up the suppressions.

[dapengzhang0]

@graememorgan Thanks for the PR.