Migrate @Provides methods to @Binds methods where possible.

@Binds is a much more efficient way to delegate one binding to another in that:
  * The @Binds method does not need to be invoked
  * It does not generate an additional Provider implementation
  * An additional Provider does does not need to be instantiated
Future changes to Dagger's component processor will add even further benefits.

More information: []

ATTENTION REVIEWERS: This migration is being done with global approval.  Per-project approval is not required.

Tested:
    TAP train for global presubmit queue
    []
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125980758

java/google/registry/dns/DnsModule.java

@@ -27,6 +27,7 @@ import static google.registry.request.RequestParameters.extractSetOfParameters;
 import com.google.appengine.api.taskqueue.Queue;
 import com.google.appengine.api.taskqueue.QueueFactory;
 
+import dagger.Binds;
 import dagger.Module;
 import dagger.Provides;
 
@@ -42,13 +43,11 @@ import javax.servlet.http.HttpServletRequest;
 
 /** Dagger module for the dns package. */
 @Module
-public final class DnsModule {
+public abstract class DnsModule {
 
-  @Provides
+  @Binds
   @DnsWriterZone
-  static String provideZoneName(@Parameter(RequestParameters.PARAM_TLD) String tld) {
-    return tld;
-  }
+  abstract String provideZoneName(@Parameter(RequestParameters.PARAM_TLD) String tld);
 
   @Provides
   @Named(DNS_PULL_QUEUE_NAME)