cam-service: Fix start to event timeout condition

The timeout from the CAM start packet to the first event
is checked by the state timer, it checks that the start message
is sent by ensuring the state is CAM_STREAM_STATE_IN_PROGRESS,
but it should also check that the sequence_id we expect is zero,
because that is the condition of the first event message, so the
current check is not complete.

Fix this issue checking also the sequence_id.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>