Minor pip menu changes

- Skip hiding the menu when not resizing and going from CLOSE -> FULL
  state
- Separate enter/resize/exit animation durations, make the button
  dismiss anim a little faster as per mocks (will probably need to be
  tweaked further)
- Remove the slow menu fade as well to get closer to mocks, it's
  already got a fade out interpolator

Bug: 183756396
Test: Show/hide the pip menu
Change-Id: Ie10d03cb3e26253498d668ffde1a822530bbf598