Support chinaeast2 region in luis build

[feich-ms]

Is your feature request related to a problem? Please describe.
In luis build cmd, chinaeast2 region is targetting https://chinaeast2.api.cognitive.azure.cn instead of https://${region}.api.cognitive.microsoft.com. To support this, luis builder interface need to be changed.

Describe the solution you'd like
Change interface of luis builder function.

Describe alternatives you've considered
Change interface of luis builder function.

Additional context
Add any other context or screenshots about the feature request here.

[enhancement]