[PiP2] Add PipExpandAnimatorTest

Added the PipExpandAnimatorTest for PipExpandAnimator class.
PipExpandAnimator class is optimized for testing as well in this change

- Allow supplying SurfaceControlTransactionFactory for testing purpose
- Use the local animation listener since they are implementation details
- Switch over to AnimatorListenerAdapter to avoid unnecessary,
  un-testable functions such as onAnimationRepeat

Flag: com.android.wm.shell.enable_pip2
Bug: 376133026
Test: atest WMShellUnitTests:PipExpandAnimatorTest
Change-Id: I8a04d9689f231011680152bb68556deb4ca8ae4f