Add anomaly detection method to AnomalyUtils

So we could reuse it in different loaders.

Bug: 63900914
Test: robotests still pass
Change-Id: I038085f53b9d0a05b8c4849c7544567434885821

src/com/android/settings/fuelgauge/anomaly/AnomalyLoader.java

@@ -98,15 +98,7 @@ public class AnomalyLoader extends AsyncLoader<List<Anomaly>> {
                     mUserManager.getUserProfiles());
         }
 
-        final List<Anomaly> anomalies = new ArrayList<>();
-        for (@Anomaly.AnomalyType int type : Anomaly.ANOMALY_TYPE_LIST) {
-            if (mPolicy.isAnomalyDetectorEnabled(type)) {
-                anomalies.addAll(mAnomalyUtils.getAnomalyDetector(type).detectAnomalies(
-                        mBatteryStatsHelper, mPackageName));
-            }
-        }
-
-        return anomalies;
+        return mAnomalyUtils.detectAnomalies(mBatteryStatsHelper, mPolicy, mPackageName);
     }
 
     @VisibleForTesting