Android Java: Calculate SHA1 hash of file

For Android Java API 8 through 18 Write a function that can generate the SHA1 hash of any given file. The function should output the SHA1 value and the time it took to generate the hash in milliseconds. This function must be as optimized as possible for speed. The SHA1 calculation must occur in an asynctask doInBackground function, and the result posted to the activity on a textview in PostExecute You may use any built-in function provided by Android's API, but must not use any third party library. "Terms of payment" Upon awarding the job, a milestone will be created for the "entire" amount owed. Freelancer will hold this money, but none of the milestone will be released until the job is 100% complete. Do not ask for any milestone payments until all the work is 100% finalized. Its important to note, that since Freelancer will hold ALL the funds, you have NO risk of not getting paid as long as the job is done properly and in a timely manner. Bid responses sent to us that are automated - will be ignored, please do not send us automated bids if you want to be taken seriously. If you would like to be considered, please make sure to read the above requirements carefully. This is a straight forward project that should take 2 to 3 hours for a programmer that "knows" how to code in Android Java.