Release Metric v0.32.2

[MrAlias]

Added

• Added an example of using metric views to customize instruments. (Add an example of view #3177)
• Add default User-Agent header to OTLP exporter requests (go.opentelemetry.io/otel/exporters/otlpmetric/otlpmetricgrpc and go.opentelemetry.io/otel/exporters/otlpmetric/otlpmetrichttp). (Add User-Agent header to OTLP exporter requests #3261)

Changed

• Flush pending measurements with the PeriodicReader in the go.opentelemetry.io/otel/sdk/metric when ForceFlush or Shutdown are called. (Flush pending telemetry when ForceFlush or Shutdown are called on a PeriodicReader #3220)
• Update histogram default bounds to match the requirements of the latest specification. (Update bucket default bounds #3222)

Fixed

• Use default view if instrument does not match any registered view of a reader. (Default view should not be required when other views passed #3224, Use default view if instrument does not match any pipeline view #3237)
• Return the same instrument every time a user makes the exact same instrument creation call. (Duplicate instrument registration generates an error instead of a valid instrument #3229, Handle duplicate Aggregators and log instrument conflicts #3251)
• Return the existing instrument when a view transforms a creation call to match an existing instrument. (Compatible aggregators should not error instrument creation #3240, Handle duplicate Aggregators and log instrument conflicts #3251)
• Log a warning when a conflicting instrument (e.g. description, unit, data-type) is created instead of returning an error. (Handle duplicate Aggregators and log instrument conflicts #3251)
• The OpenCensus bridge no longer sends empty batches of metrics. (Improve test coverage, and don't send empty batches in OC bridge #3263)