Contrib/Resource: Fix a typo in test. (#1904)

Author: songy23

contrib/resource_util/src/test/java/io/opencensus/contrib/resource/util/ContainerResourceTest.java

@@ -27,7 +27,7 @@
 @RunWith(JUnit4.class)
 public class ContainerResourceTest {
   private static final String NAME = "container";
-  private static final String IMAGE_NAME = "iamge_name";
+  private static final String IMAGE_NAME = "image_name";
   private static final String IMAGE_TAG = "image_tag";
 
   @Test