Allow others to read the profile ref dir

ART wants to optimize the time when the profile information
is saved for an app. To do so, it needs access to both, the current
profile, and the reference profile. This will allow ART to access
the ref profiles, which previously was not needed.

Test: m & flash
Bug: 185979271
Change-Id: Ie07bce81d2fba9c0b0ae4f322418e960c024e15d