[enhancement] Report on data usage per voice/video call

[lofidevops]

User story: I am an everyday user switching to Riot/Matrix. After a call, I'd like to see how much data I used, so I can compare the cost to a regular phone call.

Suggested solution: After a voice/video call is ended display the call length and data used. For example, "Call took 5m 32s and used 10 MiB."

Out of scope for this suggestion:

• Total data use (this is reported and logged by Android already)
• Reporting data usage for other granularities:
  • Messaging (MiB per room per day)
  • Background data (MiB per day)
• Logging data usage
• Reporting actual cost based on network data rate
• ...these may be useful, but shouldn't be blockers to a simple call report

[ylecollen]

I don't think we have such stats from third party lib.