cs RAB: add nAS_SynchronisationIndicator

This is mimicking the IEs found in a trace from a production 3G environment. We
have no reason to add this other than knowing that other operators seem to do
this.

This came up while trying to fix voice RAB for the nano3G, but this patch had
no effect on that. Now that it's here, we might as well keep it.

Change-Id: I14c22b0befb308bac2eded662fe13a58c8478743
2 files changed