Merge "Add a warning message about missing gcert at the end of the build" am: 4e3c2660

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2078459



Change-Id: I8274f0a1602d86d896ebebafa03635c4618647d9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>