chore(all): auto-regenerate .pb.go files (googleapis#708)

This is an auto-generated regeneration of the .pb.go files by
cloud.google.com/go/internal/gapicgen. Once this PR is submitted, genbot will
update the corresponding PR to depend on the newer version of go-genproto, and
assign reviewers. Whilst this or any regen PR is open in go-genproto, genbot
will not create any more regeneration PRs. If all regen PRs are closed,
gapicgen will create a new set of regeneration PRs once per night.

If you have been assigned to review this PR, please:

- Ensure that CI is passing. If it's failing, it requires your manual attention.
- Approve and submit this PR if you believe it's ready to ship. That will prompt
genbot to assign reviewers to the google-cloud-go PR.

Corresponding google-cloud-go PR: googleapis/google-cloud-go#5030

Changes:

build: upgrade Java microgenerator to v2.2.1
  # v2.2.1

  ## Bug Fixes
  - gax batching regression (googleapis#863) (3a6f168)

  # v2.2.0

  ## Features
  - Add REST AIP-151 LRO suport (cb1b534)
  - enable self signed JWT for http (googleapis#850) (aba0ec0)
  - Implement DIREGAPIC LRO annotations (googleapis#832) (d7b29e0)
  - REGAPIC initial implementation (googleapis#824) (fdcfe70)
  - REGAPIC Multitransport implementation (grpc+rest) (googleapis#833) (445daf4)

  ## Bug Fixes
  - [bazel] fix rest transport handling in assembly rule (googleapis#835) (92f7c1c)
  - DIREGAPIC LRO generated tests logic (googleapis#838) (8ae8e6f)
  - fix diregapic-lro logic (googleapis#834) (957f69a)

  PiperOrigin-RevId: 405492216
  Source-Link: googleapis/googleapis@4381242

docs: clarified meaning of the legacy editions docs: clarified semantic of the streaming APIs
  PiperOrigin-RevId: 405426307
  Source-Link: googleapis/googleapis@a51c341

docs: fix docstring formatting
  Committer: @parthea
  PiperOrigin-RevId: 405015203
  Source-Link: googleapis/googleapis@974ad5b