This is a frustrating problem. Don't understand why in my company's production systems, the standard VMware installation instructions don't work.
I had no issues on my home lab. (hair pulling)
You configure the new hostname using the instructions from the vMA user guide, configuration is done through the web interface on port 5480 and/or directly from the VM console, and/or from a SSH session.
The moment you reboot the system, it reverts back to localhost.localdomain. It does not matter if you initiate the reboot from the web interface on port 5480 or from a shell session.
Anyhow, to fix this problem, create an "A" record on the AD DNS server, then from shell run "sudo -i" (this will drop you into a root session (text color will change to red), then run Suse's network configuration utility "system-config-network-tui"
Same thing happened to my home vMA.