Resubmit "Require protobuf except for ap2a" This reverts commit 390a0cf9e345e976b314089c6932284a342afaac. Reason for revert: resubmitting once the deprecated builds targets are disabled on git_main-without-vendor (cl/632571091) Change-Id: I7e960badcde1e288bec85195b5107024a0111fa1