Fix @VisibleForTesting given the newly deployed enforcement

Generated code is now also covered by @VisibleForTesting, including Dagger @Inject

This CL is a cleanup of auto-generated code by ghm@ from the Error Prone team

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=228748874

java/google/registry/tools/ShellCommand.java

@@ -297,7 +297,6 @@ public class ShellCommand implements Command {
     return resultBuilder.build().toArray(new String[0]);
   }
 
-  @VisibleForTesting
   static class JCommanderCompletor implements Completor {
 
     private static final ParamDoc DEFAULT_PARAM_DOC =