By Dan Williams and Ali Sawafta JERUSALEM/RAMALLAH, West Bank (Reuters) -Israel said on Sunday it would test a bullet that killed a Palestinian-American journalist to determine whether one of its soldiers shot her and said a U.S. observer would be present. The Palestinians, who on Saturday handed over the bullet to a U.S. security coordinator, said they had been assured that Israel would not take part in the ballistics. Washington has yet to comment. The United States has a holiday weekend to mark July 4. The death of Al Jazeera reporter Shireen Abu Akleh on May 11 during an Israeli raid in th…