chore(all): auto-regenerate .pb.go files (#1039)

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.


There is no corresponding google-cloud-go PR.

Changes:

feat: add last_scanned_row_key feature
  PiperOrigin-RevId: 551191182
  Source-Link: https://togithub.com/googleapis/googleapis/commit/51e04baa9eec3bee8b3e237bfd847eb06aa66d72

regen.txt

@@ -1 +1 @@
-52a738bc51c68e5d9aabba743bb72b4feeef41b1
+51e04baa9eec3bee8b3e237bfd847eb06aa66d72