title: Firebase: Get timestamp of last user token refresh?
body: <p>I want to get the timestamp of when the user's token was last refreshed so that if it hasn't been updated for a while, I can force a refresh to make sure I have up-to-date user data (e.g. custom claims, if the token was revoked) and also to use as an approximate current time instead of relying on the user's clock.</p>
  
  <p>Is there a way to get this timestamp?</p>
  
  <p>I'm aware there's an "expiry" for the refresh token and the refresh token is updated every hour but I'm cautious the "every hour" value could change. </p>