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: I69d730e03a075b2684ca03a7df0086d95e0e329f
Ref: CYNGNOS-291