Pull request: bamboo-specs: use our docker image in snap stage

Merge in DNS/adguard-home from spec-snap-docker to master

Squashed commit of the following:

commit 2a43d33
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Apr 8 17:51:07 2021 +0300

    bamboo-specs: use our docker image in snap stage

bamboo-specs/release.yaml

@@ -10,7 +10,7 @@
   'outputPush': 'false'
 
 'stages':
-- 'Make snapshot':
+- 'Make release':
     'manual': false
     'final': false
     'jobs':
@@ -157,6 +157,8 @@
   - 'adg-docker': 'true'
 
 'Publish to Snapstore':
+  'docker':
+    'image': '${bamboo.dockerGo}'
   'key': 'PTS'
   'tasks':
   - 'clean'