Review Metric Public API

[cijothomas]

Review the public API for metrics before the 1st stable release. Mark anything not required by spec as internal only.

[cijothomas]

Calling out some API names which require discussion:

1. SetMaxMetricPointsPerMetricStream

[cijothomas]

static OpenTelemetry.Metrics.MeterProviderExtensions.TryFindExporter(this OpenTelemetry.Metrics.MeterProvider provider, out T exporter) -> bool

Need to check this.. Looks like this is required for the Prometheus middleware.

[cijothomas]

Closing this item, as the review is completed, and no unwanted public API remains now. (once 3161 is merged.)

[CodeBlanch]

@alanwest @cijothomas We can do this later, but should we make this prop public get/set?

opentelemetry-dotnet/src/OpenTelemetry/Metrics/MetricReaderOptions.cs

Line 32 in 02301b6

public PeriodicExportingMetricReaderOptions PeriodicExportingMetricReaderOptions { get; private set; } = new PeriodicExportingMetricReaderOptions();

Right now there is a private setter which is unusual I think for options classes in and out of our repo. I don't think IOptions will bind to a private setter, but not sure. Probably good to do just for consistency?