Set breakpoints and ensured that values were as expected at each point.
1. Sent video message to `native` client that didn't support video messages and observed `UNSUPPORTED` message in Redux that wrapped `MULTIMEDIA` message.
2. Bumped Redux persist version to trigger migration.
3. Observed that `UNSUPPORTED` message was replaced by "unshimmed` `MULTIMEDIA` message.
I'll do a lot more additional testing before landing.