Make sure PiP appears on screen when folding the device

Folding triggers onDisplayChanged callback that will update the display
layout used to compute PiP position.

However, due to race condition of the setShelfHeight handler, sometimes
the new bounds for PiP are set by using the bounds in animator from
previous display layout. That value is used as a reference when we call
onMovementBoundsChanged in PipTaskOrganizer, and thus results sometimes
in displacing PiP outside of the visible screen bounds when folding.

Test: manually, via temporary log statement in the "if" body to verify
the trigger condition
Test: before http://recall/-/fj1xzZpuaq8SChahfwQ86e/dXk0Qq0aeOSbqoiMSoazIm
Test: after http://recall/-/fj1xzZpuaq8SChahfwQ86e/eHOB8F62DUS9d284FpWk7R
Bug: 263211281

Change-Id: Ibfa68f94bc81797d55c33c0aafcc937e04079a53