* Pre-Greek vote preps by central banks reassure * Volatility seen persisting ahead of Greek election * Read on NY manufacturing comes in weaker than expected * Indexes up: Dow 0.5 pct, S&P 0.6 pct, Nasdaq 0.6 pct By Ryan Vlastelica NEW YORK, June 15 (Reuters) - U.S. stocks rose on Friday on optimism major world central banks will take coordinated action if the closely watched election in Greece this weekend results in market turmoil. The news offset the latest round