Take InstanceType for launchconfig res creation

Take the init value of InstanceType for launchconfig
resource creation, since heat will apply nova flavor
custom constraint for launchconfig resource,
see: https://review.openstack.org/#/c/134879/

Change-Id: I23c6032f49104880dc6b424d115ff437f698f5c6

tempest/api/orchestration/stacks/templates/non_empty_stack.yaml

@@ -7,6 +7,8 @@ Parameters:
     Default: not_yet
   image:
     Type: String
+  flavor:
+    Type: String
 Resources:
   fluffy:
     Type: AWS::AutoScaling::LaunchConfiguration
@@ -16,7 +18,7 @@ Resources:
       - Stinky
     Properties:
       ImageId: {Ref: image}
-      InstanceType: not_used
+      InstanceType: {Ref: flavor}
       UserData:
         Fn::Replace:
         - variable_a: {Ref: trigger}

tempest/api/orchestration/stacks/test_non_empty_stack.py

@@ -31,13 +31,15 @@ class StacksTestJSON(base.BaseOrchestrationTest):
         template = cls.read_template('non_empty_stack')
         image_id = (CONF.orchestration.image_ref or
                     cls._create_image()['id'])
+        flavor = CONF.orchestration.instance_type
         # create the stack
         cls.stack_identifier = cls.create_stack(
             cls.stack_name,
             template,
             parameters={
                 'trigger': 'start',
-                'image': image_id
+                'image': image_id,
+                'flavor': flavor
             })
         cls.stack_id = cls.stack_identifier.split('/')[1]
         cls.resource_name = 'fluffy'