Move IPip and IPipAnimationListener to common

Move IPip.aidl and IPipAnimationListener.aidl to common.pip
package as a part of PiP2 refactoring.

Make sure users of these Binder interfaces in Launcher
also reference the updated classname and package.

The plan is to use these interfaces to implement
PiP2 <-> Launcher IPC to facilitate transitions and animations
for gesture nav and auto-enter PiP for instance.

Note: this CL shouldn't yield any behavioral changes.

Bug: 325481148
Test: mp droid
Change-Id: I671c57eab0b56e87db672ba9e10d8af33c6707d3