升级安装APK兼容Android7.0，解决FileUriExposedException
见http://blog.csdn.net/ruancoder/article/details/67639621?utm_source=itdadao&utm_medium=referral
见http://blog.csdn.net/ruancoder/article/details/67639621?utm_source=itdadao&utm_medium=referral
