As a vCenter Server administrator, you can create a custom vCenter Server role and assign privileges to it.
A service account is used by the App Volumes Manager to communicate with vCenter Server. The default administrator role can be used for this service account, but you can create a vCenter Server role with certain privileges, specifically for the App Volumes service account.
You can also use PowerCLI to create a custom role. See Create a Custom vCenter Server Role Using PowerCLI.