This patch fixes an uninitialized variable issue in
mm_ublox_parse_ugcntrd_response_for_cid(), which uses an uninitialized
`match_info' when `in_cid' is invalid.
The implementation uses +UGCNTRD=? to query whether the per-PDP context
statistics are supported by the device, and if they are, +UGCNTRD is used to
query them.
We only process the statistics for the specific CID we're using.
The parser returns only the results for the CID being specified as input. This
is so that we can just query the statistics of the CID currently in use by the
bearer.
Changing current allowed/preferred modes requires the device to be in low-power
mode, so we will make sure we return an error if any power operation is already
ongoing when a new one is requested.
AT+URAT=? provides the format expected, but looks like it isn't implemented
differently for the different u-blox devices seen, so we need an additional
level of filtering which currently is applied per device model string.
