Add Battery Defender feature to Settings

- Reupload CL from ag/13108999 to fix the merge conflict
 - Adding new tips of Battery Defender, will be presented once battery is overheated
 - Launch Help Center article of battery overheat when clicking Battery Defender tip
 Screenshots: https://screenshot.googleplex.com/7jUibTJANgR6UQ6.png
 	      https://screenshot.googleplex.com/tUj2LLi87SfndBN.png

Bug: 172794045
Bug: 173497281
Bug: 173496188
Test: make RunSettingsRoboTests -j40
Change-Id: Ibb106a5d42cdf6232abf9ddf4b3225bdcebccf4a

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

@@ -403,6 +403,13 @@ public class BatteryUtils {
         Log.d(tag, message + ": " + (System.currentTimeMillis() - startTime) + "ms");
     }
 
+    /**
+     * Return {@code true} if battery is overheated and charging.
+     */
+    public static boolean isBatteryDefenderOn(BatteryInfo batteryInfo) {
+        return batteryInfo.isOverheated && !batteryInfo.discharging;
+    }
+
     /**
      * Find package uid from package name
      *