Remove unnecessary explicit generic type declarations

They can be inferred correctly even in Java 7, and display as
compiler warnings in IntelliJ.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=173451087

java/google/registry/batch/ExpandRecurringBillingEventsAction.java

@@ -113,7 +113,7 @@ public class ExpandRecurringBillingEventsAction implements Runnable {
             new ExpandRecurringBillingEventsReducer(isDryRun, persistedCursorTime),
             // Add an extra shard that maps over a null recurring event (see the mapper for why).
             ImmutableList.of(
-                new NullInput<Recurring>(),
+                new NullInput<>(),
                 createChildEntityInput(
                     ImmutableSet.<Class<? extends DomainResource>>of(DomainResource.class),
                     ImmutableSet.<Class<? extends Recurring>>of(Recurring.class))))));