Add TtsSpan for formatted time.

Talk back will read "Used for 3m" as "Used for 3 meters", but
it will read "Used for 3h 3m" correctly.

This cl add specific Ttsspan if the time only contains "minute"

Bug: 36379530
Test: Run SettingsRoboTests

Change-Id: I033575938cce24221980dddd9d66be4e18804541

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

@@ -57,6 +57,8 @@ import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
+import org.robolectric.RuntimeEnvironment;
+
 import org.robolectric.annotation.Config;
 import org.robolectric.util.ReflectionHelpers;
 
@@ -140,6 +142,7 @@ public class AdvancedPowerUsageDetailTest {
 
         mFragment.mHeaderPreference = mHeaderPreference;
         mFragment.mState = mState;
+        mFragment.mBatteryUtils = new BatteryUtils(RuntimeEnvironment.application);
         mAppEntry.info = mock(ApplicationInfo.class);
 
         mTestActivity = spy(new SettingsActivity());