Update battery stuff to use SettingsLib Estimate class

This will make the upcoming consistency Cl easier to implement.

Test: Robotests still pass
Bug: 124030091
Change-Id: Ief4989e2b5f9b83b5c3b93d17f9f9fa12136f3ee

tests/robotests/src/com/android/settings/fuelgauge/BatteryInfoTest.java

@@ -41,6 +41,7 @@ import com.android.settings.testutils.BatteryTestUtils;
 import com.android.settings.testutils.FakeFeatureFactory;
 import com.android.settings.widget.UsageView;
 import com.android.settingslib.R;
+import com.android.settingslib.fuelgauge.Estimate;
 
 import org.junit.Before;
 import org.junit.Test;