All indication in CI is that Centos Stream9's use of dhclient
appears to point to compatability issues when interacting with
dnsmasq. However, this doesn't appear to be the issue with the
internal dhcp client. As such, lets constraint the RH default
so that it no longer applies to Centos 9-stream.
I've also added a documentation entry for DIB_DHCP_CLIENT which
was previously undocumented.
As an aside, I've already reached out to RH's NetworkManager team
regarding this, but root cause is not entirely understood at this
point.
Change-Id: I235f75b385a8b0348c8fe064038c51409f8722c4
Story: 2010109
Task: 45677
5f01bd5d61