Rename test

Author: schmidt-sebastian

firebase-firestore/src/test/java/com/google/firebase/firestore/model/ObjectValueBuilderTest.java renamed to firebase-firestore/src/test/java/com/google/firebase/firestore/model/MutableObjectValueTest.java

@@ -29,15 +29,15 @@
 
 @RunWith(RobolectricTestRunner.class)
 @Config(manifest = Config.NONE)
-public class ObjectValueBuilderTest {
+public class MutableObjectValueTest {
   private String fooString = "foo";
   private Value fooValue = wrap(fooString);
   private String barString = "bar";
   private Value barValue = wrap(barString);
   private Value emptyObject = Value.newBuilder().setMapValue(MapValue.getDefaultInstance()).build();
 
   @Test
-  public void supportsEmptyobjectValues() {
+  public void supportsEmptyObjectValues() {
     ObjectValue objectValue = new ObjectValue();
     assertEquals(new ObjectValue(), objectValue);
   }