Fix bugs with discovery of collection requirements

Addresses some cases where
  collection requirements do not exist
  collection requirements cannot be evaluated

Consolidate logic for roles and collection installs

awx/playbooks/project_update.yml

@@ -147,6 +147,8 @@
         args:
           chdir: "{{project_path|quote}}/collections"
         register: galaxy_collection_result
+        when: doesCollectionRequirementsExist.stat.exists
+        changed_when: "'Installing ' in galaxy_collection_result.stdout"
 
       when: collections_enabled|bool
       delegate_to: localhost