The Pentagon is getting into the booming wearable tech business, announcing a $171 million public-private partnership Friday with Silicon Valley players to produce leading-edge products for both the consumer market and the battlefield. The Department of Defense awarded the FlexTech Alliance, a tech research consortium, $75 million over five years to develop and manage the country’s newest Manufacturing Innovation Institute in San Jose, the first of several similar federally funded institutes to be located on the West Coast.