If your VirtualBox host does not have enough RAAM / memory allocated to it then it might be running little slow and hence the ambari server startup might be taking little longer than the default time set for it.
The following error just indicates that your Ambari Server is taking
slightly more than default 50 Seconds time to open port 8080 and hence
you see this message.
REASON: Server not yet listening on http port 8080 after 50 seconds. Exiting.
You should try the following to fix this:
Edit the "/etc/ambari-server/conf/ambari.properties" and increase the following property value to 120 or 150 seconds.
Then restart the ambari-server again.
# ambari-server restart
Also pelase see the"Fixed Issues"section here:https://docs.hortonworks.com/HDPDocuments/Ambari-188.8.131.52/bk_ambari-release-notes/content/ambari_reln... (Search for "AMBARI-20220")