I'm unable to complete the upgrade process, and I'm unable to understand how to fix it.
Fortunately I can still restart the old VCSA, but I cannot complete the upgrade
I hope the following logs can put someone smarter than me to the right direction

If it helps, I can copy the 10MB support bundle
VCSA ISO: VMware-VCSA-all-7.0.2-18356314.iso
firstbootStatus.jason reports: "failedSteps": "vpostgres-firstboot"
Indeed the file below has an error message
vpostgres-firstboot.py_52704_stderr.log
2021-09-21T22:43:08.875Z Upgrade import step failed
2021-09-21T22:43:08.875Z vPostgres firstboot(action=firstboot) failed
Unfortunately the file below does not report any error and ends with the copied few lines
vpostgres-firstboot.py_52704_stdout.log
...
ALTER TABLE
Successfully restarted service vmware-vpostgres
2021-09-21T22:43:08.875Z Removing temp file /tmp/tmpcfyl153w
2021-09-21T22:43:08.875Z Removing temp file /tmp/tmpx0a73gt9
2021-09-21T22:43:08.875Z Removing temp file /tmp/tmpsk28tc5c
2021-09-21T22:43:08.875Z Removing temp file /tmp/tmpd6xnxsrp
2021-09-21T22:43:08.876Z Removing temp file /tmp/tmpqlop0hhq
2021-09-21T22:43:08.876Z Removing temp file /tmp/tmpp2t4l9lu
2021-09-21T22:43:08.876Z Removing temp file /tmp/tmps9kks0yz
The following file reports an error, and the last lines are attached
firstbootInfrastructure.log
2021-09-21T22:42:17.43Z INFO firstbootInfrastructure Running firstboot script: ['/opt/vmware/bin/python', '/usr/lib/vmware-vpostgres/firstboot/vpostgres-firstboot.py', '--action', 'firstboot', '--compkey', 'vpostgres', '--errlog', '/var/log/firstboot/vpostgres-firstboot.py_52704_stderr.log']
2021-09-21T22:43:08.915Z INFO firstbootInfrastructure [Failed] /usr/lib/vmware-vpostgres/firstboot/vpostgres-firstboot.py is complete
2021-09-21T22:43:08.923Z INFO firstbootInfrastructure No localized error detail found in /var/log/firstboot/vpostgres-firstboot.py_52704_stderr.log, assuming internal error
2021-09-21T22:43:08.925Z WARNING firstbootInfrastructure Bug component info file does not exist
2021-09-21T22:43:08.925Z INFO firstbootInfrastructure Firstboot duration: 86 sec
2021-09-21T22:43:08.926Z INFO firstbootInfrastructure First boot is a failure
2021-09-21T22:43:08.927Z ERROR firstbootInfrastructure Installation of vCenter server failed with firstboot scripts
2021-09-21T22:43:08.927Z WARNING firstbootInfrastructure stopping status aggregation...