Factor out explicit animation types for the stash/unstash animations. am: 2ebfc41966 am: 5172dd3e36

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/22359836

Change-Id: I25371fc12c63fa7eff1f49f32c4cc22416dba5bd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>