[automerger skipped] Merge "Don't allow background apps to change theme" into sc-v2-dev am: a6f7644e am: 3142c5b5 -s ours

am skip reason: Merged-In I2086b29ef9bf3bb6fb7d9ebba6e7b8db9392e459 with SHA-1 04d4c040 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16203175

Change-Id: Ia8ce346b0d64b660828dff53b04c3bdedceee316