What issue type does this pull request address? (keep at least one, remove the others)
/kind bugfix

What does this pull request do? Which issues does it resolve? (use resolves #<issue_number> if possible)
resolves #

N/A

Please provide a short message that should be published in the DevSpace release notes
Fixed an issue where DevSpace check for only kustomization.yaml extension

What else do we need to know?
added support for kustomization.yml extension as well.