Use end-bounds for pip-animations that start in the end state

PIP animations usually animate from start to end bounds. However,
there are some animations where the whole animation is in the
end bounds (specifically fade-in). So, make sure to sync the
pip bounds-state to the end-bounds when doing one of these
animations.

Bug: 227214914
Test: atest WMShellFlickerTests:PipRotationTest
Change-Id: I85d5afdcd6b72a82628bf157781dd446a297846a