Whoops. No. :-(
This is an oversight in the REST API glue. We really should allow you
to define a new top level collection in your plugin, and then within
that allow your plugin name to be the default plugin name instead of
"gerrit". Unfortunately there are some hard coded assumptions into the
code about the default name being "gerrit".
I would define this as a bug in the glue code. You should be able to
do what you asked.