API Changes

• connectivity: remove unused, experimental Reporter interface (#3875)

New Features

• xds bootstrap: support insecure and make Creds required (#3881)
• xds: add bootstrap support for certificate providers. (#3901)
• lrs: add a layer for clusters in load store (#3880)
• credentials/xds: implementation of client-side xDS credentials. (#3888)

Bug Fixes

• http2_client: fix reader segfault on PROTOCOL_ERRORs (#3926)
  • Special Thanks: @sorah
• internal/transport: handle h2 errcode on header decoding (#3872)
  • Special Thanks: @tz70s
• xds: exit from run() goroutine when resolver is closed. (#3882)
• credentials/alts: ClientAuthorizationCheck to case-fold compare of peer SA (#3792)
  • Special Thanks: @AntonNep
• service reflection: include transitive closure for a file (#3851)
• stats: include message header in stats.InPayload.WireLength (#3886)
  • Special Thanks: @xstephen95x
• binarylog: export Sink (#3879)
• service reflection: include transitive closure for a file (#3851)