add releaseChannel to deployment template #29726

Swagger ApiDocPreview failed

Rule	Message
`❌` RestBuild error	"logUrl":"https://apidrop.visualstudio.com/Content%20CI/_build/results?buildId=453446&view=logs&j=fd490c07-0b22-5182-fac9-6d67fe1e939b", "detail":"The term 'Get-AzAccessToken' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again."