Changed %lld to use mingw supported PRId64

src/core/ext/client_config/channel_connectivity.c

src/core/lib/profiling/basic_timers.c

src/core/lib/security/credentials/jwt/jwt_credentials.c

src/core/lib/surface/channel.c

src/core/lib/surface/completion_queue.c

src/core/lib/transport/transport_op_string.c