Googleapis-artman

Bump ARTMAN_VERSION env var in Dockerfile

Bug fix from protoc-docs-plugin: use keyword based dict construction instead of dict literals.

Bug fix from gapic-generator: choose paged methods as the example when there are no other methods.

gapic-generator:
- update license year
- support empty method signatures
- stop guessing entity names for patterns of multi-pattern resources
- use string literals in samples for an any resource name if there is no other resources

proto-resource-name-plugin:
- support the new multi-pattern resource names in Java

protoc-docs-plugin:
- fix the error when there are comments on options

New features:

- node.js: feat: add explicit require for mocha https://github.com/googleapis/gapic-generator/pull/3063
- python: un-deprecate resource name functions https://github.com/googleapis/gapic-generator/pull/3062
- python: deprecation warning for Python 2.7 https://github.com/googleapis/gapic-generator/pull/3059
- bazel-related fixes

Including latest changes:
- https://github.com/googleapis/gapic-generator/pull/3045 Fix "proto" provider regression
- https://github.com/googleapis/gapic-generator/pull/3047 use protobuf v3.10.0 for Java