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

services/core/java/com/android/server/StorageManagerService.java

@@ -1135,8 +1135,6 @@ class StorageManagerService extends IStorageManager.Stub
             Slog.wtf(TAG, e);
         }
 
-        onKeyguardStateChanged(false);
-
         mHandler.obtainMessage(H_COMPLETE_UNLOCK_USER, userId).sendToTarget();
     }
 
@@ -1148,6 +1146,8 @@ class StorageManagerService extends IStorageManager.Stub
             mPmInternal.migrateLegacyObbData();
         }
 
+        onKeyguardStateChanged(false);
+
         // Record user as started so newly mounted volumes kick off events
         // correctly, then synthesize events for any already-mounted volumes.
         synchronized (mLock) {