A discovery in iOS 7 beta 4 appears to confirm that an upcoming iPhone will include a fingerprint sensor. Hamza Sood tweeted a picture of a folder titled “BiometricKitUI.axbundle” within the code of the upcoming operating system. From the description, it appears that the code is describing a thumbprint sensor located within the Home Button of an iPhone. It also appears that a user will need to “enroll” in volunteering a thumbprint…