Compute Platform Versions for Azure API management service

Hello MaximSokoloff, 

Across IaC there isn't a means to specifically point to STV1 or STV2.  At the time of this response, any new deployment of API Management will deploy as STV2 unless the following criteria is met:  1) new instance 2) VNET injected 3) set to internal mode 4) deployed without providing an IP address.  

Please check out our landing zone repo for TF samples:  apim-landing-zone-accelerator/reference-implementations/AppGW-IAPIM-Func/terraform at main · Azure/apim-landing-zone-accelerator · GitHub.