[automerger skipped] [RESTRICT AUTOMERGE] Add hide-non-system-overlay flag for HarmfulAppWarningActivity am: 53ee9c24 am: be7090b0 -s ours am: b0cb54d5 -s ours am: 053326ec -s ours am: 1d63bf03 -s ours am: 38db60d1 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16743244

Change-Id: I7a6dcfb78f7d226f6d10b425dce8ab3e1dae1d15