This method is documented that it may only be called in `STATE_OPENED`
or `STATE_OPENED_WITH_KEYS`. It's possible for it to be called in other
states (like `STATE_ERROR`) without this guard.
Previously this didn't cause issues, but since 9d62845c45
we assume that the `sessionId` is non-null in this method, which results
in an `IllegalStateException` when the documented state restriction is
ignored.
PiperOrigin-RevId: 675969256
0b86f89498