[Elastic-SAN] az elastic-san create: Make --base-size-tib and --extended-capacity-size-tib optional with default value of 20 and 0#8718

calvinhzy merged 2 commits intoAzure:mainAzure/azure-cli-extensions:mainfrom

calvinhzy:elastic-san-size-optionalcalvinhzy/azure-cli-extensions:elastic-san-size-optionalCopy head branch name to clipboard