is_system_jdk should be set to 1 in java-17-openjdk on all CentOS & RHEL 9 branches. See:

https://pkgs.devel.redhat.com/cgit/rpms/java-21-openjdk/commit/?h=rhel-10-main&id=c80d8b609e18484c884b6dc6f629ba2bab6f885f

which was the same change made in RHEL 10 to make java-21-openjdk the default.

This is an RPM level change and there is no need to rebuild the portable from the OPENJDK-3073 security update. A new full OpenJDK build will be needed for RHEL 9.0 only.