[Test] Fix test_build_image_custom_components by ensuring that the right custom component script is executed on all Ubuntu versions.

Author: gmarciani

tests/integration-tests/tests/createami/test_createami.py

@@ -501,7 +501,7 @@ def test_build_image_custom_components(
 ):
     """Test custom components and base AMI is ParallelCluster AMI"""
     # Custom script
-    custom_script_file = "custom_script_ubuntu.sh" if os in ["ubuntu2004"] else "custom_script.sh"
+    custom_script_file = "custom_script_ubuntu.sh" if os.startswith("ubuntu") else "custom_script.sh"
 
     # Create S3 bucket for pre install scripts, to remove epel package if it is installed
     bucket_name = s3_bucket_factory()