Move onKeyguardChangded() to completeUnlockUser() (async)

Move the onKeyguardChanged() call from onUnlockUser() (sync) to
completeUnlockUser (async).

Test: adb logcat | grep "\(SystemUserUnlock\|UnlockingUser-0\)\ took"
Test: plugin a USB drive to ATV device, make sure it gets discovered
Bug: 158524880
Bug: 156220570
Change-Id: I7e92946e3326e060ee5f9f54cc71cda1bc68f784
1 file changed