Do not show task snapshot window if task bounds has changed.

Add a condition in ActivityRecord#isSnapshotCompatible that skip to
add task snapshot window if the current task bounds does not match the
tasksnapshot size.

Bug: 216079545
Test: atest ActivityRecordTests
Test: start activity from recents after modify wm size, verify there
should use splash screen starting window.

Change-Id: I62e390e74d8de42211499c47fc282bacdd95aa6f