usb:port one android gadget patch

usb:port one android gadget patch

BZ: 32120

usb: gadget: android: Don't allow changing the functions list if enabled

Change-Id: I8cb2f5b0f510eaf96b30047c9a8590486b958458
Signed-off-by: Benoit Goby <benoit@android.com>
Signed-off-by: jzhuan5 <jin.can.zhuang@intel.com>
Reviewed-on: http://android.intel.com:8080/43649
Reviewed-by: Tang, Richard <richard.tang@intel.com>
Reviewed-by: Meng, Zhe <zhe.meng@intel.com>
Tested-by: Meng, Zhe <zhe.meng@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>