Allow pip screen size to toggle on double tap

Make sure pip screen size animates to normal
or maximum size depending on the current width
when a double tap occurs

Test: manually reproduced steps in the bug listed
Test: atest WMShellUnitTests:PipDoubleTapHelperTest
Test: atest WMShellFlickerTests:ExpandPipOnDoubleClickTest

Bug: 232173973
Change-Id: Ia8ec8696fddd236f992803451f44457e974069ac