Merge "Fix potential memory leak by setting mControllers = null" into sc-v2-dev am: 96f3f2214c am: e9dcc967cc

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/16367281

Change-Id: I0df1213a585102c484e1456cdf21c8a017d76189