Android: Allow wpa_supplicant to write files to osu-info dir

Android: Allow wpa_supplicant to write files to osu-info dir

This commit allows any process running with group id of AID_WIFI to
read/write files to osu-info directory. Also, it allows other users to
read and search the osu-info directory.

This fixes issues with hs20-osu-client creating a directory for
wpa_supplicant use without wpa_supplicant actually having privileges to
write there on Android where the wpa_supplicant process does not run as
root.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>