Before this CL, SystemUiContexts were fixed to the Display metrics
when the SystemUiContexts were created. It is the same mechanism
as DisplayContext but applies to SystemUiContexts unexpectedly.
This CL makes SystemUiContexts associate with DisplayContent with
the corresponding display ID. In this way, SystemUiContext would
receive updates when there is a Display property change.
Bug: 194262507
Bug: 191064581
Test: atest InputMethodMenuControllerTest WindowContextControllerTest
Change-Id: Idd74da965c18bdbf8912bd45e89be21f652dcf93
71b2172abc