PhoneWindowManager: Add screenshot action receiver

Screenshot addition taken from commit:
navbar: fixes and drawables
https://github.com/VanirAOSP/frameworks_base/commit/a1deac7f798a4bcd34ef1561c3a99b8837f83d50

Change-Id: I6b017c23ae95d0222fadac9b7a6d9e4222285322