'he·ro noun \ˈhir-(ˌ)ō\
: a person who is admired for great or brave acts or fine qualities
: a person who is greatly admired
: the chief male character in a story, play, movie, etc.'
Hero - Definition and More from the Free Merriam-Webster Dictionary
There are many millions of people who 'admire' him 'for great or brave acts' already.
So there is NO question to be answered.
By definition, Edward Snowden IS a hero...period.