SF: Manage many-to-one DisplayDevice to layerStack mapping for input

When there is more than one DisplayDevice that is mapped to a
layerStack, we let the display that is configured to receive input take
precedence.

We log an error if there is more than one DisplayDevice that receives
input that is mapped to a layerStack.

Bug: 210779136
Test: atest libguitest
Change-Id: I1d4f3f5fab7c71e8a44e3142404dc91051312698