[HLC] Fix hard-code parameter issue of client example in readme

[MaryGao]

Currently in hlcREADME.md.hbs we hard coded the client example generation with fixed paramters, but it is not truly for all services.

Sometimes the service constructor don't have the required subscriptionId, sometimes others have additional endpoint in their contstuctor.

const subscriptionId = "00000000-0000-0000-0000-000000000000";
const client = new {{ clientClassName }}(new DefaultAzureCredential(), subscriptionId);

So we need to fix this with actual parameter states not fixed ones.