Clients should RST_STREAM(NO_ERROR) if not half-closed when receiving trailers

[ejona86]

This is the client-side version of #2162, to handle the case when intermediaries are in play. Note that the RST_STREAM can be elided if the server sent a RST_STREAM after the EOS=true. But the client can't assume the server will send such a RST_STREAM.

[ejona86]

@ericgribkoff, was this resolved?

[ericgribkoff]

Yes, OkHttp and Netty (after #4222) clients send a RST_STREAM in this scenario.