Schedule new transition on aspect ratio change only

When we receive TaskOrganizer#onTaskInfoChanged callback, there is no
need to schedule new transition if the aspect ratio remains same since
no other parameters in PictureInPictureParams affect bounds.

Bug: 150606166
Test: Next/Prev on expanded YouTube PiP
Change-Id: I69d269f379308d0d3a333ce56acd3976b4a54983