Merge "Use testapi to trigger gc in system and sysui" into sc-dev am: d193f65878 am: e6ac7be6aa

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14463337

Change-Id: I5ff21a79a70b2fb56fb57acf99e776699ed9a2c8