1.2.0-rc4 of core components

OpenTelemetry

• The PeriodicExportingMetricReader now accepts an
  ExportIntervalMilliseconds of -1 indicating an infinite export interval
  period.
  (#2982)

• Added the PeriodicExportingMetricReaderOptions.ExportTimeoutMilliseconds
  option.
  (#3038)

• Removed MetricReaderType. This enumeration was previously used when
  configuing a metric reader with an exporter to configure whether the export
  cycle would be periodic or manual (i.e., requiring a explicit call to flush
  metrics). This change affects the push-based metric exporters: OTLP, Console,
  and InMemory. For these exporters, a manual export cycle can now be achieved
  by setting PeriodicExportingMetricReaderOptions.ExportIntervalMilliseconds
  to -1.
  (#3038)

• Marked members of the MetricPoint struct which do not mutate state as
  readonly
  (#3065)

• [Bug fix] OpenTelemetryLoggerProvider is now unaffected by changes to
  OpenTelemetryLoggerOptions after the LoggerFactory is built.
  (#3055)

OpenTelemetry.Api

OpenTelemetry.Exporter.Console

• Added StatusCode, StatusDescription support to
  ConsoleActivityExporter.
  (#2929
  #3061)

• AddConsoleExporter extension method by default sets up exporter
  to export metrics every 10 seconds.

OpenTelemetry.Exporter.InMemory

OpenTelemetry.Exporter.Jaeger

• Added support for Activity Status and StatusDescription which were
  added to Activity from System.Diagnostics.DiagnosticSource version 6.0.
  Prior to version 6.0, setting the status of an Activity was provided by the
  .NET OpenTelemetry API via the Activity.SetStatus extension method in the
  OpenTelemetry.Trace namespace. Internally, this extension method added the
  status as tags on the Activity: otel.status_code and otel.status_description.
  Therefore, to maintain backward compatibility, the exporter falls back to using
  these tags to infer status.
  (#3073)

OpenTelemetry.Exporter.OpenTelemetryProtocol

• Added support for Activity Status and StatusDescription which were
  added to Activity from System.Diagnostics.DiagnosticSource version 6.0.
  Prior to version 6.0, setting the status of an Activity was provided by the
  .NET OpenTelemetry API via the Activity.SetStatus extension method in the
  OpenTelemetry.Trace namespace. Internally, this extension method added the
  status as tags on the Activity: otel.status_code and otel.status_description.
  Therefore, to maintain backward compatibility, the exporter falls back to using
  these tags to infer status.
  (#3100)

• Fixed OTLP metric exporter to default to a periodic 60 second export cycle.
  A bug was introduced in #2717 that caused the OTLP metric export to default
  to a manual export cycle (i.e., requiring an explicit flush). A workaround
  for this bug has been provided
  here.
  (#2982)

• Bumped minimum required gRPC version (2.23.0 to 2.44.0).
  Fixes issues building on Apple Silicon (M1).
  (#2963)

• Fixed issue where the configuration of an OTLP exporter could be changed
  after instantiation by altering the original OtlpExporterOptions provided.
  (#3066)

• TraceExporter to stop populating DeprecatedCode in OTLP Status.
  OpenTelemetry.Exporter.Prometheus

OpenTelemetry.Exporter.Zipkin

• Added support for Activity Status and StatusDescription which were
  added to Activity from System.Diagnostics.DiagnosticSource version 6.0.
  Prior to version 6.0, setting the status of an Activity was provided by the
  .NET OpenTelemetry API via the Activity.SetStatus extension method in the
  OpenTelemetry.Trace namespace. Internally, this extension method added the
  status as tags on the Activity: otel.status_code and otel.status_description.
  Therefore, to maintain backward compatibility, the exporter falls back to using
  these tags to infer status.
  (#3003)