ofono_client: gracefully handle Scan() failure

ofono's NetworkRegistration.Scan() method fails sporadically. On failure,
check if we are now registered to the desired network, and schedule another
scan otherwise.

For instance it fails with org.ofono.Error.Failed if the modem starts to
register internally after we started Scan() and the registering succeeds
while we are still waiting for Scan() to finsih.

Change-Id: I4a2265ee39a94daa00f525b1c7037a6775509425
1 file changed