Use new time format in BatteryInfo

1. Using "h" and "m" instead of "hrs" and "min"
2. Refactor the string to CharSequence so it won't have
TTS issue(i.e read "m" as "meter")
3. Update tests related to this part.

Bug: 37201139
Test: RunSettingsRoboTests
Change-Id: I9cadb511572b2d522d26ab337c171fa69da87475

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

@@ -769,7 +769,7 @@ public class PowerUsageSummary extends PowerUsageBase implements
                 BatteryInfo.getBatteryInfo(mContext, new BatteryInfo.Callback() {
                     @Override
                     public void onBatteryInfoLoaded(BatteryInfo info) {
-                        mLoader.setSummary(SummaryProvider.this, info.chargeLabelString);
+                        mLoader.setSummary(SummaryProvider.this, info.chargeLabel);
                     }
                 });
             });