Fixing creating repositories in other account's domain. (#45)

Author: jonjara

aws-codeartifact-repository/src/main/java/software/amazon/codeartifact/repository/CreateHandler.java

@@ -63,7 +63,7 @@ private ProgressEvent<ResourceModel, CallbackContext> createRepository(
     }
 
     private boolean hasReadOnlyProperties(final ResourceModel model) {
-        return model.getAdministratorAccount() != null || model.getName() != null;
+        return model.getName() != null;
     }
 
     private boolean isStabilized(

aws-codeartifact-repository/src/test/java/software/amazon/codeartifact/repository/CreateHandlerTest.java

@@ -544,7 +544,7 @@ public void handleRequest_invalidRequest_readOnlyProperties() {
 
         final ResourceModel model = ResourceModel.builder()
             .domainName(DOMAIN_NAME)
-            .administratorAccount("12345")
+            .name(REPO_NAME)
             .repositoryName(REPO_NAME)
             .build();