chore(bazel): update protobuf to v3.21.7 (#1020)

- [ ] Regenerate this pull request now.

PiperOrigin-RevId: 477955264

Source-Link: https://togithub.com/googleapis/googleapis/commit/a724450af76d0001f23602684c49cd6a4b3a5654

Source-Link: https://togithub.com/googleapis/googleapis-gen/commit/4abcbcaec855e74a0b22a4988cf9e0eb61a83094
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiNGFiY2JjYWVjODU1ZTc0YTBiMjJhNDk4OGNmOWUwZWI2MWE4MzA5NCJ9

fix: deprecate extra field to avoid confusion

PiperOrigin-RevId: 477776089

Source-Link: https://togithub.com/googleapis/googleapis/commit/57062cd9acb65df8a1bf1293decba380c9fcca13

Source-Link: https://togithub.com/googleapis/googleapis-gen/commit/99b76b52b138a79277fcac8c46644b815c7a37d7
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Author: gcf-owl-bot[bot]

README.md

@@ -57,13 +57,13 @@ implementation 'com.google.cloud:google-cloud-dlp'
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-dlp:3.7.3'
+implementation 'com.google.cloud:google-cloud-dlp:3.7.4'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-dlp" % "3.7.3"
+libraryDependencies += "com.google.cloud" % "google-cloud-dlp" % "3.7.4"
 ```
 
 ## Authentication