Remove obsolete keystore2 atoms.

This CL removes the previously defined keystore2 pushed atoms.

Ignore-AOSP-First: No mergepath to AOSP.
Bug: 188590587
Test: statsd TestDrive script.
Merged-In: Id6c72fe65c9e58ec8f47e17dc3f9042552b3b508

Change-Id: Id6c72fe65c9e58ec8f47e17dc3f9042552b3b508