fix a few isolated dev issues

the main goal of this change is to make `make docker-isolated` work out
of the box

- specify the proper version for awx-expect --version
- update some deprecated playbook bits
- change the isolated container to privileged so bwrap will work
- fix awx-manage test_isolated_connection
- expedite the first isolated heartbeat so you don't have to wait 10m;
  this is accomplished by _not_ setting Instance.last_isolated_check to
  now() at insertion time (which causes the next check not to happen for
  10 minutes)
- fix a bug that caused isolated node execution to fail when bwrap was
  enabled

see: https://github.com/ansible/tower/issues/2150

This reverts commit 9863fe71dc.

tools/docker-isolated/Dockerfile

@@ -27,7 +27,4 @@ RUN ssh-keygen -A
 RUN mkdir -p /root/.ssh
 RUN touch /root/.ssh/authorized_keys
 
-STOPSIGNAL SIGRTMIN+3
-
-
 CMD ["/usr/sbin/init"]