Replace the config_use_tryboot boolean with a config_abRebootReason string
passed straight to PowerManager.reboot() (empty = normal reboot). RPi
overrides it to "2" so the candidate slot boots via a one-shot reboot,2
(partition 2 = boot_b); tryboot is now reserved for recovery entry. No
behavior change on devices that leave the reason empty.
oxmc
2fb8e31cfd