Only update anomaly icon in AnomalyLoader

Before this cl, it will re-calculate battery percentage once we get
anomaly data, which will add screen usage data twice. This cl make it
only update anomaly icon after the anomaly detection is done.

Bug: 62803379
Test: RunSettingsRoboTests
Change-Id: I2089646679e299fa948b1f3ed21f4a13a1317aa3

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

@@ -25,6 +25,7 @@ import android.view.View;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.TextView;
+
 import com.android.settings.R;
 import com.android.settings.TintablePreference;
 import com.android.settings.Utils;
@@ -96,6 +97,10 @@ public class PowerGaugePreference extends TintablePreference {
         notifyChanged();
     }
 
+    public boolean showAnomalyIcon() {
+        return mShowAnomalyIcon;
+    }
+
     BatteryEntry getInfo() {
         return mInfo;
     }