最近升级Android SDK Tools 报错如下：
Packages to install:
- Android SDK Tools (tools)
- Android Emulator (emulator)
Preparing "Install Android SDK Tools (revision: 26.1.1)".
Found existing prepared package.
"Install Android SDK Tools (revision: 26.1.1)" ready.
Preparing "Install Android Emulator (revision: 29.3.2)".
Downloading http://dl.google.com/android/repository/emulator-windows-6083285.zip
"Install Android Emulator (revision: 29.3.2)" ready.
Installing Android SDK Tools in E:\AppData\AndroidStudioSDK\Sdk\tools
An error occurred during installation: Failed to move away or delete existing target file: E:\AppData\AndroidStudioSDK\Sdk\tools
Move it away manually and try again..
"Install Android SDK Tools (revision: 26.1.1)" complete.
"Install Android SDK Tools (revision: 26.1.1)" failed.
Installing Android Emulator in E:\AppData\AndroidStudioSDK\Sdk\emulator
"Install Android Emulator (revision: 29.3.2)" complete.
"Install Android Emulator (revision: 29.3.2)" finished.
Failed packages:
- Android SDK Tools (tools)
把SDK下面的tools文件夹重命名toolsXX,然后继续更新SDK Tools ，等待一会，更新完成后，发现SDK下面重新生成新的tools 文件夹，把刚更新下来tools的东西全部copy到toolsXX，把tools文件夹删除，然后把toolsXX名字改过来tools。
参考：https://stackoverflow.com/questions/44052385/sdkmanager-updatesdk-on-windows-not-work
