Call roles granting only when packages changed

This computes and stores a hash of significant (for PermissionController)
packages state for the time when granting last ran.

Test: - enable DEBUG flag
- using logcat ensure roles granted on first bootloader
- adb reboot
- ensure roles granting skipped
- disable a package
- adb reboot
- ensure roles granting ran on boot

Change-Id: Idaea40c0ea34feaedfbe357627201f85e66876d5