chore(all): auto-regenerate .pb.go files (googleapis#802)

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.

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Changes:

fix(documentai): mark Document.Entity.type as REQUIRED in all versions fix: remove Document.Entity.bounding_poly_for_demo_frontend from v1beta2
  The type field was always required by the backend, so this formally breaking change can likely be accepted without bumping the major version. Field removal is in beta version so can be accepted as well.

  PiperOrigin-RevId: 444656928
  Source-Link: googleapis/googleapis@a0d4c5c

feat(dialogflow/cx): added audio_export_settings
  PiperOrigin-RevId: 444644952
  Source-Link: googleapis/googleapis@4bd299a

chore: fix typo in PACKAGES.md (googleapis#715)

  Source-Link: googleapis/googleapis@6869f2f

chore: use gapic-generator-python 0.65.2
  PiperOrigin-RevId: 444333013
  Source-Link: googleapis/googleapis@f91b6cf

chore(bazel): update version of Protobuf to v3.20.1
  PiperOrigin-RevId: 444328399
  Source-Link: googleapis/googleapis@c7ca416

regen.txt

@@ -1 +1 @@
-92c7dbc7ad6d9d0851fc00329529b8e31d4b96ba
+a0d4c5c2a714a7317714ba6f0066a74ec8a9c10b