Make index ingestion and metrics resubscribe pausing occur on connection as well

[hensmi-amazon]

Issue #: #1448

Description of changes: See title/issue. This is an extension of #1841

Testing: Smoke tested using simulcast enabled chrome browsers. Am occasionally able to see the pause/resume on connection to show it is working.

Can these tested using a demo application? Please provide reproducible step-by-step instructions.

1. Join a meeting with simulcast and enable video.
2. Join with another client and confirm video from other participants show promptly. Note that the key here is connected additional clients after video has been enabled, not joining all clients and then enabling video.

Checklist:

1. Have you successfully run npm run build:release locally?
   y

2. Do you add, modify, or delete public API definitions? If yes, has that been reviewed and approved?
   n

3. Do you change the wire protocol, e.g. the request method? If yes, has that been reviewed and approved?
   n

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.