To disable it, simple navigate to this Registry Key on the RDS server:

HKLM\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\TerminalServer\CentralPublishedResources\PublishedFarms\[FarmName]\RemoteDesktops\[FarmName]

and change the ShowInPortal REG_DWORD from 1 to 0.

Here, you can also update the RemoteApp Name by changing the value of the Name REG_SZ.

No need to restart any service after these changes.