Never store battery stats for cache

In PowerUsageBase, it will store battery stats if it has a configuration
change, which will make BatteryStatsLoaderHelper never get the correct
battery stats because it uses Bundle.EMPTY as the bundle message.

This cl:
1. Remove the store action even though it is configuration change.
2. Always use null to get battery stats
3. Always start a battery status check in register()

Bug: 63658232
Test: RunSettingsRoboTests
Change-Id: Ifbf970c63378ed66dddcdae4d952b7d1fd84216a

src/com/android/settings/fuelgauge/BatteryStatsHelperLoader.java

@@ -31,12 +31,13 @@ import com.android.settings.utils.AsyncLoader;
 public class BatteryStatsHelperLoader extends AsyncLoader<BatteryStatsHelper> {
     @VisibleForTesting
     UserManager mUserManager;
-    private Bundle mBundle;
+    @VisibleForTesting
+    BatteryUtils mBatteryUtils;
 
-    public BatteryStatsHelperLoader(Context context, Bundle bundle) {
+    public BatteryStatsHelperLoader(Context context) {
         super(context);
-        mBundle = bundle;
         mUserManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
+        mBatteryUtils = BatteryUtils.getInstance(context);
     }
 
     @Override
@@ -44,9 +45,8 @@ public class BatteryStatsHelperLoader extends AsyncLoader<BatteryStatsHelper> {
         Context context = getContext();
         final BatteryStatsHelper statsHelper = new BatteryStatsHelper(context,
                 true /* collectBatteryBroadcast */);
+        mBatteryUtils.initBatteryStatsHelper(statsHelper, null /* bundle */, mUserManager);
 
-        BatteryUtils.getInstance(context).initBatteryStatsHelper(statsHelper, mBundle,
-                mUserManager);
         return statsHelper;
     }
 
@@ -55,5 +55,4 @@ public class BatteryStatsHelperLoader extends AsyncLoader<BatteryStatsHelper> {
 
     }
 
-
 }