Googleapis-artman

In this release:

- `googleapis` inside Docker image has been updated
- Java now uses `protoc` v3.10.

No new features in this release, just the test changes.

Include the following features from gapic-generator:

- Update generated java tests to use a unique InProcessChannel name (3028)
- Assign the proto file where the method is defined (3027)
- Python: Include custom static files in generated Python docs (3020)
- test: test streaming pagination for showcase (3021)
- deprecate resource names not supported by microgenerators (3016)
- Java samplegen: replace comment-out default lines with an overload of the sample function (3019)
- samplegen: generate program.cs for c samples (3017)
- C samplegen: remove commented-out lines showing default values of parameters (3018)
- Add sample_type field to permit in-code samples. (2996)
- pin jacoco to 0.8.5 for jdk 11 compatibility (3009)
- Update dependency puppeteer to v2 (3008)

This release only includes testing and dependencies changes.

artman:
* adds grpc_service_config attribute to artman config.proto
* updates gapic_tasks to pass the --grpc_service_config generate arg using config value

Include the following changes from gapic-generator:
- unit test: honor all sample_code_init_field for expected and actual requests