Merge "aconfig_proto: add doc in aconfig.proto file" into main am: b7d4bedd am: ca5e3990

Original change: https://android-review.googlesource.com/c/platform/build/+/2945156



Change-Id: I4fa5cebc73e30534fe72847fcbf0e285c7337e5b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>