Merge "Changes to the signature of PluginManagerImpl." into sc-v2-dev am: 78f9648aec am: f3658027c3

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15558514

Change-Id: Ib91cd33e8f57b79b61790baa0c9f895ee2f49d7f