Merge "Remove the usage of device_config flag:...

Merge "Remove the usage of device_config flag: DisplayManagerService.KEY_ALLOW_ALWAYS_UNLOCKED_VIRTUAL_DISPLAYS." into tm-dev am: 0927574f am: e02e8396

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17943723



Change-Id: I6e3cc948d648c0ddd0c22534099e975689815281
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>