Apple will officially launch the iPhone 4 in India this coming Friday, May 27, according to a Wall Street Journal report. The handset will be available from both Bharti Airtel and Aircel, with the latter offering the iPhone 4 on both a post-paid and pre-paid basis. Aircel will charge 34,500 rupees (roughly $761) for 16GB models and 40,900 rupees (~$902) for 32GB versions; customers will be able to recoup some of the cost via monthly credits to their…