Update environment var for keystone bootstrap

Closes-Bug: #1861248
Related-Bug: #1855932

Change-Id: I6907729bca667459466834276513e9f0233d10d0
Depends-On: https://review.opendev.org/#/c/706862/
(cherry picked from commit 6f90cd8528)
(cherry picked from commit d35bfa0b86)

docker/services/keystone.yaml

@@ -173,14 +173,13 @@ outputs:
             start_order: 3
             action: exec
             user: root
-            # NOTE(mwhahaha): We use $$ because we're executing in python to
-            # call as shell script and passing the command to run as arguments
-            # to that shell script. So when it is called via eval, the escaped
-            # $ properly evaulates
             command:
-              [ 'keystone', '/usr/bin/bootstrap_host_exec', 'keystone' ,'keystone-manage', 'bootstrap', '--bootstrap-password', '$$KEYSTONE_BOOTSTRAP_PASSWORD' ]
+              [ 'keystone', '/usr/bin/bootstrap_host_exec', 'keystone' ,'keystone-manage', 'bootstrap' ]
             environment:
-              KEYSTONE_BOOTSTRAP_PASSWORD: {get_param: AdminPassword}
+              - list_join:
+                  - ''
+                  - - 'OS_BOOTSTRAP_PASSWORD='
+                    - {get_param: AdminPassword}
           keystone_cron:
             start_order: 4
             image: *keystone_image