Expose u-blox min elevation and min SNR parameters RTK Fix Improvements

[wrsolichin]

Solved Problem

When using the u-Blox RTK F9P with the PX4-Autopilot, I found that it will get RTK Fix, but it often drops to other fix mode. I have been reading about this issue, and encountered the following artcles: https://mowerproject.com/2020/07/06/an-even-better-rtk-fix/ and https://discuss.cubepilot.org/t/here-does-not-hold-rtk-fixed-status-reliably-help-please/1056, which mentions that increasing the CFG-NAVSPG-INFIL_MINCNO from the default 10 to 15 deg, and CFG-NAVSPG-INFIL_MINELEV from 6 dBHz to 35 dBHz ouputs a more reliable RTK Fix.

Potentially fixes #21555 by improving the RTK fix reliability issue if there is no RTCM drop out but RTK fix changes to other fix mode, although this will not handle RTCM drop outs and it's a separate issue.

Solution

• Updated the GPS Driver with the following PR: Expose u-Blox min elevation and min SNR for RTK Fix Improvement PX4-GPSDrivers#189
• Exposing the u-blox GPS Parameter to PX4 to allow modifications for the following parameters.

Note: This PR needs the GPS Driver submodule to be merged to main before merging this PR to main.