Bypass testFormatMethods if device is not using en_US resource.

Change-Id: I915e80cbca27eef563a7242b71a164be9ed90401
diff --git a/tests/src/android/text/format/cts/LocaleUtils.java b/tests/src/android/text/format/cts/LocaleUtils.java
index d6001c4..131d745 100644
--- a/tests/src/android/text/format/cts/LocaleUtils.java
+++ b/tests/src/android/text/format/cts/LocaleUtils.java
@@ -22,14 +22,10 @@
 
 public class LocaleUtils {
 
-    /** Return whether or not the specified locale is available on the system. */
-    public static boolean isSupportedLocale(Context context, Locale locale) {
-        String[] locales = context.getAssets().getLocales();
-        for (String availableLocale : locales) {
-            if (locale.toString().equals(availableLocale)) {
-                return true;
-            }
-        }
-        return false;
+    /** Return whether or not the given locale is the device's current locale. */
+    public static boolean isCurrentLocale(Context context, Locale locale) {
+        // TODO: Change the locale on the device using public API if it becomes available.
+        Locale currentLocale = context.getResources().getConfiguration().locale;
+        return locale.equals(currentLocale);
     }
 }
diff --git a/tests/tests/text/src/android/text/format/cts/DateUtilsTest.java b/tests/tests/text/src/android/text/format/cts/DateUtilsTest.java
index a5dd335..6d034b9 100644
--- a/tests/tests/text/src/android/text/format/cts/DateUtilsTest.java
+++ b/tests/tests/text/src/android/text/format/cts/DateUtilsTest.java
@@ -37,7 +37,6 @@
     private static final long HOUR_DURATION = 2 * 60 * 60 * 1000;
     private static final long DAY_DURATION = 5 * 24 * 60 * 60 * 1000;
     private long mBaseTime;
-    private Locale mDefaultLocale;
     private Context mContext;
 
     @Override
@@ -45,18 +44,6 @@
         super.setUp();
         mContext = getContext();
         mBaseTime = System.currentTimeMillis();
-        mDefaultLocale = Locale.getDefault();
-        if (!mDefaultLocale.equals(Locale.US)) {
-            Locale.setDefault(Locale.US);
-        }
-    }
-
-    @Override
-    protected void tearDown() throws Exception {
-        if (!Locale.getDefault().equals(mDefaultLocale)) {
-            Locale.setDefault(mDefaultLocale);
-        }
-        super.tearDown();
     }
 
     @TestTargetNew(
@@ -65,6 +52,10 @@
         args = {int.class, int.class}
     )
     public void testGetDayOfWeekString() {
+        if (!LocaleUtils.isCurrentLocale(mContext, Locale.US)) {
+            return;
+        }
+
         assertEquals("Sunday",
                 DateUtils.getDayOfWeekString(Calendar.SUNDAY, DateUtils.LENGTH_LONG));
         assertEquals("Sun",
@@ -86,6 +77,9 @@
         args = {int.class, int.class}
     )
     public void testGetMonthString() {
+        if (!LocaleUtils.isCurrentLocale(mContext, Locale.US)) {
+            return;
+        }
         assertEquals("January", DateUtils.getMonthString(Calendar.JANUARY, DateUtils.LENGTH_LONG));
         assertEquals("Jan",
                 DateUtils.getMonthString(Calendar.JANUARY, DateUtils.LENGTH_MEDIUM));
@@ -104,6 +98,9 @@
         args = {int.class}
     )
     public void testGetAMPMString() {
+        if (!LocaleUtils.isCurrentLocale(mContext, Locale.US)) {
+            return;
+        }
         assertEquals("am", DateUtils.getAMPMString(Calendar.AM));
         assertEquals("pm", DateUtils.getAMPMString(Calendar.PM));
     }
@@ -142,6 +139,9 @@
     })
 
     public void testGetSpanString() {
+        if (!LocaleUtils.isCurrentLocale(mContext, Locale.US)) {
+            return;
+        }
         assertEquals("0 minutes ago",
                 DateUtils.getRelativeTimeSpanString(mBaseTime - MIN_DURATION).toString());
         assertEquals("in 0 minutes",
@@ -198,8 +198,7 @@
     })
     @SuppressWarnings("deprecation")
     public void testFormatMethods() {
-        if (!LocaleUtils.isSupportedLocale(mContext, Locale.US)) {
-            // Locale is set to US in setUp method.
+        if (!LocaleUtils.isCurrentLocale(mContext, Locale.US)) {
             return;
         }