shouldShowRequestPermissionRationale()

• Returns true if the app has requested this permission previously and the user denied the request.
• If the user turned down the permission request in the past and chose the Don't ask again option, this method returns false.
• Calling shouldShowRequestPermissionRationale() first time before a permission denial will retturn false

Reference

• https://stackoverflow.com/questions/32347532/android-m-permissions-confused-on-the-usage-of-shouldshowrequestpermissionrati