At the moment reboot strategies are

edpm_reboot_strategy: force - force a reboot when reboot service is specified in openstackdataplane deployment

auto (default option) - reboot when required on greenfield deployment and do not reboot when Nova is deployed regardless if reboot is required or not

never  - do not reboot even if reboot is required

As an end user I'd like to enhance reboot strategies to cover the following use cases

1. 1 I would like to run update periodically but reboot nodes only when needs-restarting -r recommends to reboot
   This is a common scenario for environments where users can reboot data plane nodes during the maintenance window without workload evacuation. These sceenarios are common for banks and other businesses that do not require 24\7 operations of their workloads

This can be implemented by introducing a new key
edpm_reboot_strategy: enabled

Once implemented we'll have the following scenarios

1. edpm_reboot_strategy: force
   In this scenario, data plane node will be rebooted anyway no matter what needs-restarting -r recommends.

1. edpm_reboot_strategy: enabled <- more inteligent force( it needs to ignore existence of nova and take into account need-restarting)
   In this scenario, when needs-restarting -r doesn't recommend to reboot the node won't be rebooted. Otherwise it will be rebooted to apply changes that cannot be applied without reboot
2. edpm_reboot_strategy: disabled or not set (default behaviour) 
   In this scenario, data plane nodes won't be rebooted no matter what needs-restarting -r recommends. Reboot will be applied by operators using other methods.
3. edpm_reboot_strategy: auto 
   In this scenario reboot when required on greenfield deployment and do not reboot when Nova is deployed regardless if reboot is required or not