test: Bluetooth: Mesh: fix racing between bsim devices in provisioning test

Bsim devices work asynchronously before access to Phy.
Interprocess OOB communication might be broken because of this.
PR adds synchronization for devices. Drift is 100ms between them.

Signed-off-by: Aleksandr Khromykh <aleksandr.khromykh@nordicsemi.no>
1 file changed