Create a bootc experimentation sandbox by having the BootcNodeManagement FG: When the FG is on, the rpm-ostree commands will be replaced by equivalent bootc commands to manually test the capability of bootc in non-layered machine configuration workflow. Switch back to rpm-ostree as the default option when not compatible. This experimentation prepares for the scenario that "we don’t have layered update path as the default, but we start to provide rpm-ostree + bootc dual support (likely in 4.17 and 4.18)".

Implementation detail

(1) Create an update path that will invoke bootc calls inside of the daemon to perform OS content updates (e.g. osImageURL updates, Kernel Type switch, Kernel Extension change and Kernel Argument updates). 

(2) Add the ability to fall back to rpm-ostree to perform updates when the changes are bootc incompatible/not-enabled. 

(2) Assess FG - BootcNodeManagement so that bootc update path will be the default update path when the FG is on and will be turned off when the FG is off. Default workflow falls back to rpm-ostree 

Done when 

(1) The path above is well implemented and passes the functionality test. 

(2) There is a smooth transition between bootc and rpm-ostree calls for changes that are bootc compatible but not enabled