Only allow TaskDisplayArea to specify orientation if it is focused

(1/n Orientation on DisplayAreaGroup)

Record the last focused TDA and only allow it to specify orientation
if it is the last focused one on the logical display, so that when
there are multiple TDAs, we only respect the TDA with focus.

Bug: 155431879
Test: manual: test with fixed-orientation app
Test: atest WmTests:TaskRecordTests
Test: atest WmTests:TaskDisplayAreaTests
Change-Id: Ia574550368ce45a6e2c2f81b543adcfa4cf01ba1