[automerger skipped] Disallow system apps to be installed/updated as instant. am: fbdeb248db -s ours

am skip reason: Merged-In Idd89a6dd72f0e68259095f677185f0494391025c with SHA-1 0d0f185c0d is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/25718734

Change-Id: Icd94d06dd6161996c6a06eef344bf1c0314667f3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>