Fix python path when deploy host is not localhost

When we don't use localhost as deploy host, we need to use
octavia_service_setup_host_python_interpreter variable.

This variable give the correct python path (in a venv for example when
we use a utility container as a setup host)

Depends-On: https://review.opendev.org/687000
Change-Id: I65c023db3cb8080e57442f35e599a372519d97d7
Closes-Bug: 1835744
(cherry picked from commit 2e78130c544f5659abeeab2bbd193d0bbc800053)

tasks/octavia_amp_image.yml

@@ -21,8 +21,7 @@
 - name: Setup the amphora image
   delegate_to: "{{ octavia_service_setup_host }}"
   vars:
-    ansible_python_interpreter: >-
-      {{ (octavia_service_setup_host == 'localhost') | ternary(ansible_playbook_python, ansible_python['executable']) }}
+    ansible_python_interpreter: "{{ octavia_service_setup_host_python_interpreter }}"
   block:
     - name: Create image download directory
       file:

tasks/octavia_flavor_create.yml

@@ -21,8 +21,7 @@
 - name: Setup the octavia flavor
   delegate_to: "{{ octavia_service_setup_host }}"
   vars:
-    ansible_python_interpreter: >-
-      {{ (octavia_service_setup_host == 'localhost') | ternary(ansible_playbook_python, ansible_python['executable']) }}
+    ansible_python_interpreter: "{{ octavia_service_setup_host_python_interpreter }}"
   block:
     - name: Create Octavia Flavor
       run_once: true

tasks/octavia_mgmt_network.yml

@@ -21,8 +21,7 @@
 - name: Setup the network
   delegate_to: "{{ octavia_service_setup_host }}"
   vars:
-    ansible_python_interpreter: >-
-      {{ (octavia_service_setup_host == 'localhost') | ternary(ansible_playbook_python, ansible_python['executable']) }}
+    ansible_python_interpreter: "{{ octavia_service_setup_host_python_interpreter }}"
   block:
     - name: Create mgmt network
       run_once: true

tasks/octavia_security_group.yml

@@ -21,8 +21,7 @@
 - name: Setup the security groups
   delegate_to: "{{ octavia_service_setup_host }}"
   vars:
-    ansible_python_interpreter: >-
-      {{ (octavia_service_setup_host == 'localhost') | ternary(ansible_playbook_python, ansible_python['executable']) }}
+    ansible_python_interpreter: "{{ octavia_service_setup_host_python_interpreter }}"
   block:
     - name: Setup the service project quota
       os_quota: