gRPC-Core Release 1.43.0

[veb...@google.com]

This is the 1.43.0 (green) release announcement for gRPC-Core and the wrapped languages C++, C#, Objective-C, Python, PHP and Ruby. Latest release notes are here.

This release contains refinements, improvements, and bug fixes, with highlights listed below.

Core

• Remove redundant work serializer usage in c-ares windows code. (#28016)
• Support RDS updates on the server. (#27851)
• Use WorkSerializer in XdsClient to propagate updates in a synchronized manner. (#27975)
• Support Custom Post-handshake Verification in TlsCredentials. (#25631)
• Reintroduce the EventEngine default factory. (#27920)
• Assert Android API >= v21. (#27943)
• Add support for abstract unix domain sockets. (#27906)

C++

• OpenCensus: Move metadata storage to arena. (#27948)

C#

• [C#] Add nullable type attributes to Grpc.Core.Api. (#27887)

Objective-C

• Revert "Revert "[objc] GRPCMetadataDictionary convenient typedef"". (#27882)

Python

• [Aio] Validate the input type for set_trailing_metadata and abort. (#27958)