inter-BSC Handover doesn't work with Ciphering enabled
Decoding of the BSSMAP Handover Request from the MSC omits the Chosen Encryption Algorithm,
which is crucial for establishing the new lchan with identical encryption as the old lchan.
For intra-BSC handover, the previous encryption is copied from the old lchan, which of course is not available during inter-BSC handover.
Hence the lchan activation info needs to include an explicit encryption information,
and we must not rely on the presence of the previous lchan to copy encryption information from.