Default value of 'array' parameter is converted to string

### Description
If I have a pipeline with parameter of type 'array'

When I run pipeline itself and leave default value, ADF treats it as array
**UPD: attaching screenshot with pipeline parameters:**

But when I run pipeline from another pipeline and leave default value, ADF converts this default value to string

As an end user I expect that I can use default array value without sideeffects.

### Acceptance criteria
ADF treats default value of 'array' parameter as array when running pipeline from another pipeline.