wpa_supplicant(hidl): Move conf files to /data/vendor/wifi/wpa

For treble compilance, wpa_supplicant should not be accessing
/data/misc/wifi. So, change the conf file path to /data/vendor/wifi/wpa
& move existing conf files to this new path.

This is a port of the logic in
|SupplicantManager::ensure_config_file_exists()|

Bug: 36645291
Test: Device boots up and connects to wifi networks on upgrade/fresh
builds.
Test: Manually verified that the conf files are copied over to the new
path.
Change-Id: Iedfcb31e87bb9cabfcada46cf430f2c4072495c4
2 files changed