Mark optional for new constructors and interface in clientMetricReport

[ldai1]

Issue #:
Previously submitted a pr which has breaking changes for exposing video metrics: #1251

Description of changes:
This change is to make some attribute in DefaultClientMetricReport optional and make getObersableVideoMetricReport interface optional.

Also pass in attendeeId instead of audioVideoController to DefaultClientMetricReport.
Testing

1. Have you successfully run npm run build:release locally? yes
2. How did you test these changes? test in meeting demo app
3. Can these changes be tested using the demo application? If yes, which demo application can be used to test it? meetingV2
4. Do you add, modify, or delete public API definitions? If yes, has that been reviewed and approved? yes
5. Do you change the wire protocol, e.g. the request method? If yes, has that been reviewed and approved? no

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