Allow auto-pip on launching new Task from TaskBar

Loosen the check on FLAG_RESUME_WHILE_PAUSING in
TaskFragment#startPausing for auto-enter-pip.

Fixed also the round corner radius calculation in WMShell component for
entering PiP transition.

Bug: 198227082
Bug: 202574512
Video: http://recall/-/aaaaaabFQoRHlzixHdtY/bEPWcJSn8iGbLLNg6cM0E3
Test: no auto-enter on quick switch and does on launching new Task,
      see video for details
Test: atest PinnedStackTests#testAutoPipOnLaunchingAnotherActivity
Change-Id: I53e62a5f6e663b2d6df8cd0aaa858ff01ef073e8