[automerger skipped] Simplifying callback calls in PackageInstallerSession. am: 21a91cb702 am: bd36c4fe77 -s ours

am skip reason: Change-Id I6414d28ce66a925738615a448ed4fd8670ceec91 with SHA-1 2b1d32a5e7 is in history

Change-Id: Ibedb3711d93ff5dfefbe9e94f37e9495b264fb41