Simplify some of the RDAP Action classes

Overriding getter methods to change values is a bit overkill when these values
are static (don't change based on internal state).

Just setting them in the base class' constructor is simpler.

Also, we can read the PATH of an Action based on the Annotation instead
returning it manually for each Action.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=246135754

java/google/registry/rdap/RdapDomainAction.java

@@ -36,29 +36,14 @@ import org.joda.time.DateTime;
 /** RDAP (new WHOIS) action for domain requests. */
 @Action(
     service = Action.Service.PUBAPI,
-    path = RdapDomainAction.PATH,
+    path = "/rdap/domain/",
     method = {GET, HEAD},
     isPrefix = true,
     auth = Auth.AUTH_PUBLIC)
 public class RdapDomainAction extends RdapActionBase {
 
-  public static final String PATH = "/rdap/domain/";
-
-  @Inject public RdapDomainAction() {}
-
-  @Override
-  public String getHumanReadableObjectTypeName() {
-    return "domain name";
-  }
-
-  @Override
-  public String getActionPath() {
-    return PATH;
-  }
-
-  @Override
-  public EndpointType getEndpointType() {
-    return EndpointType.DOMAIN;
+  @Inject public RdapDomainAction() {
+    super("domain name", EndpointType.DOMAIN);
   }
 
   @Override