WNBA star Brittney Grinerlooked rattled with nerves as she awaits her fate for allegedly carrying vape cartridges containing hashish oil through Moscow airport security in February. The imprisoned Phoenix Mercury star, 31, appeared in a Russian courtroom on Monday for a preliminary hearing ahead of her trial, which is now set to begin on Friday, July 1, Radar can confirm. She was shackled in photos obtained by Daily Mail and will remain in custody until the trial ends, her lawyer, Aleksandr Boikov, confirmed. The 6-foot-9 athlete could be seen surrounded by prison guards ahead of her courtroom…