chore(all): auto-regenerate .pb.go files (#942)

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#7081

Changes:

docs: minor update to comments
  PiperOrigin-RevId: 489331240
  Source-Link: googleapis/googleapis@43c8e80

build: use rules_gapic v0.19.1
  PiperOrigin-RevId: 489253130
  Source-Link: googleapis/googleapis@01ab880

chore(bazel): update gapic-generator-php to v1.6.1
  PiperOrigin-RevId: 489247285
  Source-Link: googleapis/googleapis@c40ef67

docs(dialogflow/cx): Clarified Agent Assist max retention is 30 days
  PiperOrigin-RevId: 489241089
  Source-Link: googleapis/googleapis@e795029

chore: regenerate API index

  Source-Link: googleapis/googleapis@1d962cc

feat(video/transcoder): add PreprocessingConfig.deinterlace docs: minor documentation changes
  PiperOrigin-RevId: 489233360
  Source-Link: googleapis/googleapis@a186468

regen.txt

@@ -1 +1 @@
-0184330e57d223dee21501ff4c9a08e9624add47
+43c8e80a384841ec0f740e001f077d9af8a5eae8