Merge pull request #7025 from ctiller/%s

src/core/ext/client_config/subchannel_call_holder.c

src/core/ext/transport/chttp2/transport/chttp2_transport.c

src/core/ext/transport/chttp2/transport/internal.h

src/core/lib/channel/channel_stack.c

src/core/lib/iomgr/error.c

src/core/lib/iomgr/error.h

src/core/lib/security/transport/client_auth_filter.c

src/core/lib/surface/call.c

src/core/lib/surface/completion_queue.c

src/core/lib/transport/transport.c

src/core/lib/transport/transport.h

src/core/lib/transport/transport_op_string.c

test/core/end2end/tests/network_status_change.c