fix(composer): default composer image version

As of now, v3 is currently not supported by integration tests in the CI

Author: alexis974

modules/create_environment_v2/README.md

@@ -81,7 +81,7 @@ module "simple-composer-environment" {
 | env\_variables | Variables of the airflow environment. | `map(string)` | `{}` | no |
 | environment\_size | The environment size controls the performance parameters of the managed Cloud Composer infrastructure that includes the Airflow database. Values for environment size are: `ENVIRONMENT_SIZE_SMALL`, `ENVIRONMENT_SIZE_MEDIUM`, and `ENVIRONMENT_SIZE_LARGE`. | `string` | `"ENVIRONMENT_SIZE_MEDIUM"` | no |
 | grant\_sa\_agent\_permission | Cloud Composer relies on Workload Identity as Google API authentication mechanism for Airflow. | `bool` | `true` | no |
-| image\_version | The version of the aiflow running in the cloud composer environment. | `string` | `"composer-3-airflow-2.10.2"` | no |
+| image\_version | The version of the aiflow running in the cloud composer environment. | `string` | `"composer-2.10.2-airflow-2.10.2"` | no |
 | kms\_key\_name | Customer-managed Encryption Key fully qualified resource name, i.e. projects/project-id/locations/location/keyRings/keyring/cryptoKeys/key. | `string` | `null` | no |
 | labels | The resource labels (a map of key/value pairs) to be applied to the Cloud Composer. | `map(string)` | `{}` | no |
 | maintenance\_end\_time | Time window specified for recurring maintenance operations in RFC3339 format | `string` | `null` | no |

modules/create_environment_v2/variables.tf

@@ -103,7 +103,7 @@ variable "env_variables" {
 variable "image_version" {
   type        = string
   description = "The version of the aiflow running in the cloud composer environment."
-  default     = "composer-3-airflow-2.10.2"
+  default     = "composer-2.10.2-airflow-2.10.2"
 }
 
 variable "pypi_packages" {