Create test display and window only if needed

Introduce annotation UseTestDisplay so only the annotated test
class and method will create the extra display and windows when
setting up.

This may reduce the presubmit time of WmTests by 30% (~20min).

Test: atest WmTests
Bug: 154655192

Change-Id: I6ffae4d285d24eac93807bf644b4f2c8c8563b44