Fix some issues with pinch to resize

- Tweak calculation of resize bounds, calculate the scale from the change
  in distance between the pointers, and scale about the centroid of the
  pip
- Fix issue with rotation not being about the center of the pip
- Fix issue with jumping rotation on start of gesture
- Fix issue with animating to top when max bounds are used
- Fix issue with resizing while the menu is open not actually resizing
  for a brief period (the menu fading was triggering another pip
  animation)

http://recall/-/g6hkB0pXjyQSvfA8STqRAT/cW6W0tdqDzisBndgU2JnM7

Bug: 178881304
Test: Pinch to resize in the cases above
Change-Id: I3bdf535cda64b9ce1926c7081f6cc40d4d79ab69