Don't store invalid pkgs when migrating filters Test: NotificationManagerServiceTest Test: call method from test app, view policy xml file Flag: none Bug: 305926929 (cherry picked from commit bfa04e208995b05eee2a5336667f4e2dcd19fd30) (cherry picked from https://googleplex-android-review.googlesource.com/q/commit:2ca002383116ef3427f8a4f5c9b2a1aaab49c4d1) Merged-In: Ib7fcb733edd2cf2cbac0a7699763a5fe993b467e Change-Id: Ib7fcb733edd2cf2cbac0a7699763a5fe993b467e