Add the user set network mode to the siminfo table

* To track what the user set for the particular sub independent
  of the currently set network mode (i.e. PREFERRED_NETWORK_MODE)
* Useful on MSIM where the modem may only support 2G on one of the slots,
  so the preferred network mode (and the NETWORK_MODE column) would
  not always reflect the user desired network mode.

Change-Id: Iab98955ccb3955249f78cc0341d0cfa8eb195775
Ref: CYNGNOS-291