Do not set credentials via environment variables

installer/roles/local_docker/templates/credentials.py.j2

@@ -0,0 +1,22 @@
+DATABASES = {
+    'default': {
+        'ATOMIC_REQUESTS': True,
+        'ENGINE': 'django.db.backends.postgresql',
+        'NAME': "{{ pg_database }}",
+        'USER': "{{ pg_username }}",
+        'PASSWORD': "{{ pg_password }}",
+        'HOST': "{{ pg_hostname|default('postgres') }}",
+        'PORT': "{{ pg_port }}",
+    }
+}
+BROKER_URL = 'amqp://{}:{}@{}:{}/{}'.format(
+    "{{ rabbitmq_user }}",
+    "{{ rabbitmq_password }}",
+    "localhost",
+    "5672",
+    "awx")
+CHANNEL_LAYERS = {
+    'default': {'BACKEND': 'asgi_amqp.AMQPChannelLayer',
+                'ROUTING': 'awx.main.routing.channel_routing',
+                'CONFIG': {'url': BROKER_URL}}
+}