Hi Abhijit,
We use Creative Cloud Packager to package the apps we want and we have to untick the "Disable Adobe Creative Cloud desktop application" under the Advanced Configuration to make sure the CC Desktop app gets installed. We also use an internal update server so that is stated in the Advanced Configuration settings.
I can't see a way to stop the CC Desktop app to receive updates to itself if RUM doesn't cover it.
It would be great if we could get the CC Desktop app as a pkg so we can deploy new versions manually if CC Desktop app won't be included in RUM