veyron/runtimes, veyron2/model: Share preferred protocols when client is changed with RuntimeX.
veyron/runtimes, veyron2/model: Share preferred protocols when client is
changed with RuntimeX.

Change-Id: I603ea4eda1e00ebe6bbd18f3e81cbea6cae05c06

vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref