ListGroups: Accept --ownedby as an alias of --owned-by

In the release notes of 2.16 and documentation, the --owned-by option
was incorrectly documented as --ownedBy which resulted in an error if
it was used:

  "--ownedby" is not a valid option

The documentation has been fixed, but --ownedBy will still result in
an error for anyone who refers to the outdated documentation.

Add --ownedby as an alias of --owned-by so that it will work if either
is given.

Bug: Issue 12698
Change-Id: I6229b191b59d8c0bc65105ae5817104c3b40863c

java/com/google/gerrit/server/restapi/group/ListGroups.java

@@ -205,7 +205,10 @@ public class ListGroups implements RestReadView<TopLevelResource> {
     options.addAll(ListGroupsOption.fromBits(Integer.parseInt(hex, 16)));
   }
 
-  @Option(name = "--owned-by", usage = "list groups owned by the given group uuid")
+  @Option(
+      name = "--owned-by",
+      aliases = {"--ownedby"},
+      usage = "list groups owned by the given group uuid")
   public void setOwnedBy(String ownedBy) {
     this.ownedBy = ownedBy;
   }