wifi: Reset autoscan timer on a new scan

wifi: Reset autoscan timer on a new scan

Setting device scanning to false will clean up all networks not
seen so far. If a user scan happens to be requested while the
emulated background scan is running, the background scan will
be cancelled and the non-discovered networks cleared. This causes
unnecessary clearing and re-discovery of WiFi networks when the
user scan is completed.

Create a reset autoscan function that will only reset the autoscan
parameters and not set device scanning to false. Call this function
when starting a scan.