[RESTRICT AUTOMERGE][pm] prevent system app downgrades of versions lower than preload am: 224da6d4 am: d9092a87

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21159679



Change-Id: I3ef858bb8bd260fecf4152b401fff9c66f641ca7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>