Add a persistence mechanism for panels' packages am: e192a439 am: 479f4f61

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20928108



Change-Id: I36c2fedd9de9c5890ba75a252c45bbe070ead91c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>