Merge "Move input surfaces into its own overlay in DisplayContent" into udc-qpr-dev

...ava/com/android/server/input/GestureMonitorSpyWindow.java

...re/java/com/android/server/input/InputManagerService.java

...d/server/inputmethod/HandwritingEventReceiverSurface.java

services/core/java/com/android/server/wm/DisplayContent.java

...core/java/com/android/server/wm/InputManagerCallback.java

...core/java/com/android/server/wm/WindowManagerService.java