Remove unnecessary generic type arguments

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=175155365

java/google/registry/dns/writer/clouddns/CloudDnsWriter.java

@@ -121,7 +121,7 @@ public class CloudDnsWriter extends BaseDnsWriter {
     // desiredRecordsBuilder is populated with an empty set to indicate that all existing records
     // should be deleted.
     if (!domainResource.isPresent() || !domainResource.get().shouldPublishToDns()) {
-      desiredRecords.put(absoluteDomainName, ImmutableSet.<ResourceRecordSet>of());
+      desiredRecords.put(absoluteDomainName, ImmutableSet.of());
       return;
     }
 
@@ -189,7 +189,7 @@ public class CloudDnsWriter extends BaseDnsWriter {
 
     // Return early if the host is deleted.
     if (!host.isPresent()) {
-      desiredRecords.put(absoluteHostName, ImmutableSet.<ResourceRecordSet>of());
+      desiredRecords.put(absoluteHostName, ImmutableSet.of());
       return;
     }
 

java/google/registry/dns/writer/dnsupdate/DnsUpdateWriter.java

@@ -203,7 +203,7 @@ public class DnsUpdateWriter extends BaseDnsWriter {
         union(
             domain.getSubordinateHosts(),
             (additionalHost == null
-                ? ImmutableSet.<String>of()
+                ? ImmutableSet.of()
                 : ImmutableSet.of(additionalHost)))) {
       update.delete(toAbsoluteName(hostName), Type.ANY);
     }