Facia content api calls count

When pushing all the `datapoints` to `CloudWatch` in the past, we were able to get the amount of times a `FrontendTimingMetric` has been called via `Data Points` and then also the `average`, `maximum`, `sum` and `minimum`.

After I refactored the `FrontendTimingMetric` to make less `CloudWatch` calls, we lost the use of `DataPoints` since this is now being flattened.

This just adds the amount of times the `FrontendTimingMetric` `ElasticHttpTimingMetric` gets called; the amount of Content API requests.

@robertberry @stephanfowler