Fix filed test case in BatteryInfoTest

Root cause: the test case has timezone dependency, it need to set
timezone before run the test case or it will be failed on different
timezone.
Solution: Replace AlarmManager.setTimeZone with TimeZone.setDefault,
AlarmManager.setTimeZone() seems failed to change timezone for test case.

Fix: 333857349
Test: http://ab/I51500010265016400
Change-Id: Id36dd10866720cba19cce471d294e09272c8091f

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

@@ -31,7 +31,6 @@ import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
-import android.app.AlarmManager;
 import android.content.Context;
 import android.content.Intent;
 import android.os.BatteryManager;
@@ -48,6 +47,7 @@ import com.android.settings.testutils.FakeFeatureFactory;
 import com.android.settings.widget.UsageView;
 import com.android.settingslib.fuelgauge.Estimate;
 
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -62,6 +62,7 @@ import java.time.Duration;
 import java.time.Instant;
 import java.util.Locale;
 import java.util.Map;
+import java.util.TimeZone;
 import java.util.concurrent.TimeUnit;
 
 @RunWith(RobolectricTestRunner.class)
@@ -102,6 +103,7 @@ public class BatteryInfoTest {
     private Intent mChargingBatteryBroadcast;
     private Context mContext;
     private FakeFeatureFactory mFeatureFactory;
+    private TimeZone mOriginalTimeZone;
 
     @Mock private BatteryUsageStats mBatteryUsageStats;
 
@@ -123,6 +125,13 @@ public class BatteryInfoTest {
 
         // Reset static cache for testing purpose.
         com.android.settingslib.fuelgauge.BatteryUtils.setChargingStringV2Enabled(null);
+
+        mOriginalTimeZone = TimeZone.getDefault();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        TimeZone.setDefault(mOriginalTimeZone);
     }
 
     @Test
@@ -668,7 +677,7 @@ public class BatteryInfoTest {
             String expectedRemainingLabel,
             String expectedChargeLabel) {
         mContext.getResources().getConfiguration().setLocale(Locale.US);
-        mContext.getSystemService(AlarmManager.class).setTimeZone("UTC");
+        TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
         var info =
                 BatteryInfo.getBatteryInfo(
                         mContext,