Walmart has announced that it is dropping the price of the iPhone 4 to $147 through the remainder of June. According to the company, the lower price is good for both black and white versions and for both GSM and CDMA models, and requires a new two-year agreement or qualified upgrade. We have contacted a representative of the company for claification as to whether there is a similar discount on 32GB models and will update this report as soon as we…