Vendor collections for isolated jobs to work in ansible 2.10

kubectl and synchronize are now part of community.kubernetes
and ansible.posix collections, respectively. This change installs
these collections to a local directory to be used in inventory and
isolated management playbooks.

awx issue #6930

awx/playbooks/check_isolated.yml

@@ -5,6 +5,8 @@
 - name: Poll for status of active job.
   hosts: all
   gather_facts: false
+  collections:
+    - ansible.posix
 
   tasks:
 

awx/playbooks/run_isolated.yml

@@ -9,6 +9,8 @@
   gather_facts: false
   vars:
     secret: "{{ lookup('pipe', 'cat ' + src + '/env/ssh_key') }}"
+  collections:
+    - ansible.posix
 
   tasks:
     - name: synchronize job environment with isolated host