Add keystore permission for metrics re-routing.

Keystore2 atoms need to be rounted to statsd via a proxy.
The proxy needs to have this permission in order to pull metrics from
keystore.

Ignore-AOSP-First: No mergepath to AOSP.
Bug: 188590587
Test: Statsd Testdrive script
Change-Id: Ic94f4bb19a08b6300cfd2d3ed09b31d5b7081bfd
12 files changed