Remove unnecessary type specifications

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=179585680

javatests/google/registry/model/common/TimedTransitionPropertyTest.java

@@ -148,7 +148,7 @@ public class TimedTransitionPropertyTest {
         IllegalArgumentException.class,
         () ->
             TimedTransitionProperty.fromValueMap(
-                ImmutableSortedMap.<DateTime, String>of(), StringTimedTransition.class));
+                ImmutableSortedMap.of(), StringTimedTransition.class));
   }
 
   @Test