我按照AddAWSMobileUserSignIn中的说明进行操作代码如下:publicclassLoginActivityextendsAppCompatActivity{@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_login);AWSMobileClient.getInstance().initialize(this,newAWSStartupHandler(){@Overrid