The variables mKeyguardDisabled and mAllowDisableKeyguard were being modified unprotected by mKeyguardTokenWatcher. Fix is to serialize accesses to these variables by only referencing them from the same Handler that mKeyguardTokenWatcher uses. Eliminates synchronization blocks and mKeyguardDisabled variable. Fixes bug 7045624. Change-Id: I6355aa393507408296316bee61e178dc81e2a172