title: When using Native Stack is there a new JS context created on different screens/tabs?
body: <p>This is more of an implementation question for React Navigation Native Stack.</p>
  <p>When using Native Stack, is there a new JS context created?  I am asking because I am using <code>async-mutex</code> which assumes there's a single JS Context and will ensure locks are maintained.</p>
  <p>I am using that to lock access to Expo SQLite as SQLite does not appear to block when starting up a transaction using <code>BEGIN</code>.</p>