add isMiWifi method to WifiManager

N/A

Change-Id: Ic5e8a31b5c19d2de9bccba3144f325f8c85ca37a
Signed-off-by: mochangming <mochangming@xiaomi.com>
amend miui hook

Change-Id: I9b5196fc04111203adbb96e8fffea24e92b86847