Allow multiuser use of keystore

Since keystore has been refactored to let muliple users use it
simultaneously, we can remove all the restrictions put into place to
prevent it.

(cherry picked from commit cc48b0104e4d81592055a578a33f2a59f29bf907)

Bug: 7249554
Change-Id: I419474151380c29e49e50451befbbdf3af65b175
2 files changed