Allow metric store to be configured

[justinvdm]

The sms and ussd app configs will need to include a field for the metric store once this lands.

[hodgestar]

This will require a config update in the conversations that use it, but otherwise :+1: from me.

[imsickofmaps]

@justinvdm what does the config now look like?

[justinvdm]

@imsickofmaps The config will now need a metric_store field. So the actual USSD and SMS conversation configs will look something like this:

{
...
  "metric_store": "ghr_metrics"
...
}

and the QA SMS and USSD conversation configs will look something like:

{
...
  "metric_store": "ghr_qa_metrics"
...
}

That way, we can keep all 4 conversations on the GHR Go account.

[imsickofmaps]

:+1: