Revert "Prevent leak of transition leashes in RemoteAnimationRunnerCompat."

This reverts commit 0955ae43.

Reason for revert: part of a revert chain to CP fix to b/404507270. The end state is the same as currently at ToT, but need to have cherry-pickable CLs for branches that are in CP mode.
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:d980405713bd9876f7301116e648f1d88b460eba)
Merged-In: I3c3eb66f2ab59d16598394f754279e441eb89e85
Change-Id: I3c3eb66f2ab59d16598394f754279e441eb89e85