What is the result of click the Button1 in the code which is illustrated in the following image? Assuming that write_to_external_storage is the name of an activity that allows users to write to external storage.

What is the purpose of adding the following permission tag to your app's AndroidManifest.xml file?
Content providers can help an application manage access to data stored by it or by other apps. They also provide a way to share data with other apps.
A digital certificate is an electronic ''passport'' that allows a person, computer or organization to exchange information securely over the Internet using the public key infrastructure (PKI).The message is encrypted with the Private key, and can only be decrypted with the Public key.
A manifest file (AndroidManifest.xml) describes the components of the application, which include the activities, services, broadcast receivers, and content providers that compose the application.