Revert "Add entry in readme for proto files"

This reverts commit 2aa9a52.

Author: daymxn

firebase-vertexai/README.md

@@ -30,8 +30,3 @@ the [spotless plugin]([https://plugins.jetbrains.com/plugin/14912-ktfmt](https:/
 by running:
 
 `./gradlew firebase-vertexai:spotlessApply`
-
-## Proto definitions
-
-You can find the actual proto definitions that we translate to on the
-[googleapis repo](https://github.com/googleapis/googleapis/tree/master/google/ai/generativelanguage).