Fix issue #16555033: Battery history overflowing too much

Use new mechanism to retrieve battery stats, now that they
can be much larger.

Make sure these will ever end up going through an IPC.

Change-Id: Ic582a61d736e24bddc905082c1565ece00fcbb29

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

@@ -47,8 +47,6 @@ public class BatteryHistoryPreference extends Preference {
         setLayoutResource(R.layout.preference_batteryhistory);
         mStats = stats;
         mBatteryBroadcast = batteryBroadcast;
-        // Make it non selectable
-        setSelectable(false);
     }
 
     BatteryStats getStats() {