Allow possibility to disable heatstack password

This allow the possibility to disable the heat stack password field.

Change-Id: I8dcf212398570c5d124bac769614b968d8b8cb12
(cherry picked from commit 2d6664d3c5)

defaults/main.yml

@@ -101,6 +101,7 @@ horizon_enforce_password_check: False
 horizon_disable_password_reveal: False
 horizon_enable_password_retrieve: False
 horizon_enable_password_autocomplete: False
+horizon_enable_heatstack_user_pass: True
 # If nova_libvirt_inject_password is set to True, then this can also be enabled:
 horizon_can_set_password: False
 horizon_enable_cinder_backup: False

releasenotes/notes/heatstack_password-25956b6143577735.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - It's now possible to disable heat stack password field in horizon.
+    ``horizon_enable_heatstack_user_pass`` variable has been added and
+    default to True.

templates/horizon_local_settings.py.j2

@@ -311,7 +311,7 @@ OPENSTACK_NEUTRON_NETWORK = {
 # The OPENSTACK_HEAT_STACK settings can be used to disable password
 # field required while launching the stack.
 OPENSTACK_HEAT_STACK = {
-    'enable_user_pass': True,
+    'enable_user_pass': {{ horizon_enable_heatstack_user_pass }},
 }
 
 # The OPENSTACK_IMAGE_BACKEND settings can be used to customize features