Mark OTA update as valid.
Must be called after an OTA update and reboot to confirm the new firmware works.
May also be called after a reboot without OTA update.
If the system reboots before an OTA update is accepted
the update will be marked as aborted and will not be booted again.
Explicitly mark an OTA update as invalid.
May be called after an OTA update failed, but is not required.
If the system reboots before an OTA update is confirmed as valid
the update will be marked as aborted and will not be booted again.