[battery-statefs] Work around unreliable change notifications. JB#43282
[battery-statefs] Work around unreliable change notifications. JB#43282

Getting change notifications from fuse fs has never worked reliably and
despite already present mitigation code there are several devices where
battery related properties "freeze" - which can cause assorted problems
and glitches around the system.

Do a forced statefs battery property re-read on every system heartbeat,
resume from suspend and when usb cable is connected/disconnected.

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

spiiroin/mce,spiiroin/mce,spiiroin/mce,spiiroin/mce