[display] Handle compositor exit during setUpdatesEnabled call. JB#47846
[display] Handle compositor exit during setUpdatesEnabled call. JB#47846

Once mce has issued a setUpdatesEnabled method call, it expects to get a
reply even if compositor service drops from SystemBus. While the situation
does self correct when a fresh compositor instance shows up, hiccups like
unwarranted ipc panic led pattern triggering can occur before that.

Explicitly wake up display state machine also when compositor service
drops from system bus.

Do not treat compositor service stopped state as "ipc pending".

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

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