fix: update app-cef-infoblox_nios.conf file to correctly classify the…

[cwadhwani-splunk]

… cef formatted logs. Updated the readme file with correct sourcetype and key

[mstopa-splunk]

@cwadhwani-splunk please update both:

fd "app-cef-infoblox_nios.conf"
package/etc/conf.d/conflib/cef/app-cef-infoblox_nios.conf
package/lite/etc/addons/infoblox/app-cef-infoblox_nios.conf

and please change it from draft to PR to run the CI pipeline