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 am: b1fe1c30

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



Change-Id: I75870ad2f5858e44539a81d883c3de2e955840e4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>