[移动开发]安卓user版本默认开启debug模式，默认adb能连接

亲测有效! 在展锐sl8541e android8.1代码包上面测试，只需修改两点

1.默认为debug打开模式,默认ro.debuggable=1（默认允许debug）

build/make/core/main.mk

ifeq (true,$(strip $(enable_target_debugging)))
   INCLUDE_TEST_OTA_KEYS := true
 else # !enable_target_debugging
   # Target is less debuggable and adbd is off by default
-  ADDITIONAL_DEFAULT_PROPERTIES += ro.debuggable=0
+  ADDITIONAL_DEFAULT_PROPERTIES += ro.debuggable=1
 endif # !enable_target_debugging

2.去掉? ?连上USB线之后，界面弹出是否授权连接的弹出框，并默认授权连接

        public void onReceive(Context content, Intent intent) {
            String action = intent.getAction();
            if (!UsbManager.ACTION_USB_STATE.equals(action)) {
                return;
            }
            //boolean connected = intent.getBooleanExtra(UsbManager.USB_CONNECTED, false);
			boolean connected = false; //default set false
            if (!connected) {
                mActivity.finish();
            }
			//add begin
			try {
			IBinder b = ServiceManager.getService(USB_SERVICE);
			IUsbManager service = IUsbManager.Stub.asInterface(b);
			service.allowUsbDebugging(true, mKey);
			} 
			catch (Exception e) {
			Log.e(TAG, "Unable to notify Usb service", e);
			}
            //add end

        }