1.5.1-beta.1 of instrumentation libraries

For all the four instrumentation libraries: AspNetCore, HttpClient, GrpcNetClient, SqlClient:

• The new HTTP and network semantic conventions can be opted in to by setting
  the OTEL_SEMCONV_STABILITY_OPT_IN environment variable. This allows for a
  transition period for users to experiment with the new semantic conventions
  and adapt as necessary. The environment variable supports the following
  values:
  • http - emit the new, frozen (proposed for stable) HTTP and networking
    attributes, and stop emitting the old experimental HTTP and networking
    attributes that the instrumentation emitted previously.
  • http/dup - emit both the old and the frozen (proposed for stable) HTTP
    and networking attributes, allowing for a more seamless transition.
  • The default behavior (in the absence of one of these values) is to continue
    emitting the same HTTP and network semantic conventions that were emitted in
    1.5.0-beta.1.
  • Note: this option will eventually be removed after the new HTTP and
    network semantic conventions are marked stable. At which time this
    instrumentation can receive a stable release, and the old HTTP and
    network semantic conventions will no longer be supported. Refer to the
    specification for more information regarding the new HTTP and network
    semantic conventions for both spans and metrics.

OpenTelemetry.Instrumentation.AspNetCore

• Fixed an issue affecting NET 7.0+. If custom propagation is being used
  and tags are added to an Activity during sampling then that Activity would be dropped.
  (#4637)