When sharing first stream to User (with only Reader role), Searching the stream fails.

## Expected Behavior

The list of streams in a session should always be up to date with the streams you are allowed to see.

## Current Behavior

## Possible Solution

## Steps to Reproduce (for bugs)
1. Create a new User with the reader role
2. Login as this user in a different Session/Browser
3. Share a stream with this user
4. in the other session, go to the Streams page, you can see the stream
5. click on the stream, you see the error message that you have no streams to search on
6. initiate a full page reload
7. searching the stream now works

## Context

## Your Environment

* Graylog Version: 6.0-rc2
* Java Version:
* OpenSearch Version:
* MongoDB Version:
* Operating System:
* Browser version: