Rename metrics exporter option MetricExportInterval to MetricExportIntervalMilliSeconds

[utpilla]

Addresses the PR comment: #2192 (comment)

Changes

• Rename the metrics exporter option MetricExportInterval to MetricExportIntervalMilliSeconds for Console, InMemory and OTLP exporter

[cijothomas]

I expect there would be more renamings, if/when spec gives this parameter a name

[codecov]

Codecov Report

Merging #2193 (66c86e7) into main (28f59eb) will not change coverage.
The diff coverage is 25.00%.

@@           Coverage Diff           @@
##             main    #2193   +/-   ##
=======================================
  Coverage   74.68%   74.68%           
=======================================
  Files         217      217           
  Lines        6948     6948           
=======================================
  Hits         5189     5189           
  Misses       1759     1759           

Impacted Files	Coverage Δ
...InMemory/InMemoryExporterMetricHelperExtensions.cs	0.00% <0.00%> (ø)
...metry.Exporter.InMemory/InMemoryExporterOptions.cs	0.00% <0.00%> (ø)
...etryProtocol/OtlpMetricExporterHelperExtensions.cs	0.00% <0.00%> (ø)
...orter.OpenTelemetryProtocol/OtlpExporterOptions.cs	100.00% <100.00%> (ø)
...ter.ZPages/Implementation/ZPagesActivityTracker.cs	97.14% <0.00%> (-2.86%)	⬇️
...ZPages/Implementation/ZPagesExporterEventSource.cs	62.50% <0.00%> (+6.25%)	⬆️

[CodeBlanch]

Sorry late on this one but I think Milliseconds is more standard than MilliSeconds. In our repo and also dotnet/runtime.