[state] Allow cancellation of battery empty shutdown. JB#41302
[state] Allow cancellation of battery empty shutdown. JB#41302

Even if user plugs charger immediately after battery empty shutdown
notification, DSME still triggers the shutdown.

The battery empty shutdown sequence is: notification, delay, transition
to shutdown state, delay, invoking shutdown via init/systemd. The point
of no return is at state change, so we can still cancel shutdown if a
charger is connected during notification period.

Signed-off-by: Simo Piiroinen <6d5e5360bed3d486f7d9fb26b0f737f7d4fd45ee@jollamobile.com>

spiiroin/dsme,spiiroin/dsme