Fix nit in LocaleDataTest#testInvalidLocale and StringTest#testFormat_invalidLocale

The test were introduced by afe00b2f2be215ce74f920363a47daafb6e907ff
(http://r.android.com/944499)

Test: LocaleDataTest
Test: StringTest
Bug: 129070579
Change-Id: If2d1c88705ab6a8e3cc855f6a957ffc33641dc84
diff --git a/luni/src/test/java/libcore/java/lang/StringTest.java b/luni/src/test/java/libcore/java/lang/StringTest.java
index 045581d..c440ebe 100644
--- a/luni/src/test/java/libcore/java/lang/StringTest.java
+++ b/luni/src/test/java/libcore/java/lang/StringTest.java
@@ -783,13 +783,13 @@
     }
 
     /**
-     * Regression test for b/129070579: String.format() would throw a RuntimeException when the
-     * default locale was set to an unknown/invalid locale.
+     * Check that String.format() does not throw when the default locale is invalid.
+     * http://b/129070579
      */
     public void testFormat_invalidLocale() {
         Locale defaultLocale = Locale.getDefault();
         try {
-            Locale.setDefault(new Locale("abc"));
+            Locale.setDefault(new Locale("invalidLocale"));
             String.format("%s", "");
         } finally {
             Locale.setDefault(defaultLocale);
diff --git a/luni/src/test/java/libcore/libcore/icu/LocaleDataTest.java b/luni/src/test/java/libcore/libcore/icu/LocaleDataTest.java
index 316a806..607397d 100644
--- a/luni/src/test/java/libcore/libcore/icu/LocaleDataTest.java
+++ b/luni/src/test/java/libcore/libcore/icu/LocaleDataTest.java
@@ -139,11 +139,11 @@
     assertFalse(haw.shortDateFormat.isEmpty());
   }
 
-    /**
-     * Regression test for b/129070579: LocaleData.get() would throw a RuntimeException when the
-     * default locale was set to an unknown/invalid locale.
-     */
+  /**
+   * Check that LocaleData.get() does not throw when the input locale is invalid.
+   * http://b/129070579
+   */
   public void testInvalidLocale() {
-    LocaleData.get(new Locale("abc"));
+    LocaleData.get(new Locale("invalidLocale"));
   }
 }