Sync the Mastodon service and sls name

Summary:
Fixes the following error:

Specified SLS roles/paas-docker/containers.mastodon_sidekiq in saltenv base
is not available on the salt master or through a configured fileserver

Test Plan: salt dwellers state.sls roles/paas-docker/containers

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D2105