Two stars. Unrated. In Hebrew, English, German and Polish with subtitles. 109 minutes. By Mark Jenkins, Special To The Washington Post Burrowing backward from 1970s Israel to 1940s Poland, “Past Life” is a family melodrama in the guise of a murder mystery. Strong performances and the shadow of the Holocaust lend the story poignancy. But writer-director Avi Nesher has adapted a real-life memoir — Baruch Milch’s “Can Heaven Be Void?” — into an overly contrived dramatic scenario.