Add instrumentation tags to grpc metrics

[stanley-cheung]

Add two tags to the A66 metrics exported by the MetricsStreamTracers

  'instrumentation_source': 'grpc-spring'
  'instrumentation_version': {current project version}

[stanley-cheung]

[ EDIT: the following error has been fixed. ]

$ ./gradlew publishToMavenLocal


> Task :grpc-common-spring-boot:sourcesJar FAILED

FAILURE: Build failed with an exception.

* What went wrong:
A problem was found with the configuration of task ':grpc-common-spring-boot:sourcesJar' (type 'Jar').
  - Gradle detected a problem with the following location: '/usr/local/google/home/stanleycheung/grpc-spring/grpc-common-spring-boot/src/main/java'.
    
    Reason: Task ':grpc-common-spring-boot:sourcesJar' uses this output of task ':createVersionsFile' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':createVersionsFile' as an input of ':grpc-common-spring-boot:sourcesJar'.
      2. Declare an explicit dependency on ':createVersionsFile' from ':grpc-common-spring-boot:sourcesJar' using Task#dependsOn.
      3. Declare an explicit dependency on ':createVersionsFile' from ':grpc-common-spring-boot:sourcesJar' using Task#mustRunAfter.

[stanley-cheung]

Some more work to be done...

[ST-DDT]

Add two tags to the A66 metrics exported by the MetricsStreamTracers

I haven't found a reason why these tags should be included. Is it part of the spec?

[stanley-cheung]

Add two tags to the A66 metrics exported by the MetricsStreamTracers

I haven't found a reason why these tags should be included. Is it part of the spec?

Yes this is part of an internal spec that will help us distinguish where the metrics originate.

[ST-DDT]

I'm not sure whether the tags should be included for everyone.
But implementation wise this looks good to me.
(Spring has a bean for adding tags to metrics).

[DNVindhya]

LGTM