Verified this bug with latest 4.5 ARM templates, and works. After installation, check master OSDisk size, it is showing on Azure portal: Disk Configuration: 1024 GiB (Premium SSD)
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:2909