Revert "Fixing security vuln by tightening race condition window."

This reverts commit ef4f067c03543d8c8f2f8218bc69af12692ba000.

Reason for revert: The underlying system support required to properly fix this bug has been implemented. This patch-over is no longer necessary. Patches listed in b/25646100
Test: atest keystore_unit_tests
Change-Id: I8e3e78f1440a81e60ab4986c5bb07df205a60062
1 file changed