DONOTMERGE: Fix null as default in deployParams

[jordlay]

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Important: we have not merged this because it feels like the wrong solution. The ideal solution is to fix the bug in the RP that means that defaultValues cannot be null at the nfdv stage.

If there is a null type, the default is null. AOSM doesnt allow this at nfdv publish stage. To workaround this, we check if the default is none, and add it to required if not.

Testing Completed:

• tested with helm chart that had a null type, it didnt add a default, and added the param to required. It also kept the defaults for all the other params
• all the way to sns

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