[containers_common] Including the layers.json file

gather the file '/var/lib/containers/storage/overlay-layers/layers.json'
to help to troubleshoot any RHOCP DiskPressure on nodes.
Related to: #4283
Signed-off-by: Vincent Lours <vlours@redhat.com>

Signed-off-by: Vincent Lours <42592162+vlours@users.noreply.github.com>

Author: vlours

sos/report/plugins/containers_common.py

@@ -29,6 +29,7 @@ def setup(self):
             '/usr/share/containers/*',
             '/etc/subuid',
             '/etc/subgid',
+            '/var/lib/containers/storage/overlay-layers/layers.json'
         ])
 
         self.add_file_tags({