Fix Notification animation controller memory leak

This fixes leaking of NotificationLaunchAnimatorController instances (together with their referenced Notification entries) by breaking a dependency cycle through IPC.
Also removes completion callback - it's a very easy avenue to leak even more objects accidentally and is currently unused in SysUI code.

Bug: 299069405
Bug: 298028699
Bug: 293929945
Test: unit tests for attached class. Reproduced issue on cheetah,
confirmed fix of issue with a profiler.
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:0e46bbbd75ca8c3e9aa30f68d3c47015ca786e6c)
Merged-In: Ib17577cba17ed35b24c4ab32ce0ed55fc7a24605
Change-Id: Ib17577cba17ed35b24c4ab32ce0ed55fc7a24605