Teach persistable Uri grants about direct boot

We read the persistable Uri grants on boot at which point
the user is not unlocked. This results in ignoring Uri
grants for boot unaware content providers.

This change reads all persisted Uri grants on boot but
filters them out during query based on the current user
unlock state.

bug:29058113

Change-Id: I2643fc098f42359e72a4c534236debc9b9389256