Move Launcher classes shared between tests and prod in a separate lib am: e8ee34ad8a am: e4287dfd10

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/21083963

Change-Id: I120d3625a9f96627f3565a207144c7888351acd6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>