Make the variable type for the GitLab CI secret configurable
What does this MR do?
Makes the secret variable type configurable.
Why was this MR needed?
Initially the secret variable was hardcoded to bye of type file. This change allows to configure the type with the API job payload. Leaving the file as the default when the API doesn't define it.
This makes the change backward compatible and doesn't create a hard binding with GitLab Rails implementation that must be added separately to support new syntax.
What's the best way to test this MR?
What are the relevant issue numbers?
Related to gitlab#250695 (closed)
Edited by Tomasz Maczukin