Finish moving all UID/GID callers to single AIDL method that requires callers to provide flags. Triage AppWidgets and PrintServices, which currently can only live on internal storage; we should revisit that later. Fix two bugs where we'd drop pending install sessions and persisted Uri grants for apps installed on external storage. Bug: 26471205 Change-Id: I66fdfc737fda0042050d81ff8839de55c2b4effd