vlr: when setting IMEISV, also set IMEI

Copy IMEISV to IMEI when IMEISV changes. The additional SV digits will
get cut off then. This is needed for the subscriber on demand use case,
since we can get the IMEISV early (see [1]), but need to send the IMEI
to the Check IMEI procedure.

While adjusting the tests, I have noticed that there are code paths
where we ask the MS for the IMEISV first, and later ask the MS for the
IMEI, although we already have the IMEISV. This could be improved in a
future patch.

[1] Change-Id I256224194c3b8caf2b58a88d11dccd32c569201f

Related: OS#2542
Change-Id: I02e7b66848bf7dddb31b105e2ae981432817ae1e
3 files changed