添加focusBorder insted of enabledBorder

Add focusBorder insted of enabledBorder

TextFormField(
        decoration: InputDecoration(
          labelText: "Resevior Name",
          fillColor: Colors.white,
          focusedBorder:OutlineInputBorder(
            borderSide: const BorderSide(color: Colors.white, width: 2.0),
            borderRadius: BorderRadius.circular(25.0),
          ),
        ),
      )