Switch from deprecated RSocketClientChannel to RocketClientChannel
Switch from deprecated RSocketClientChannel to RocketClientChannel

Summary:
`RSocketClientChannel` is deprecated in favor of `RocketClientChannel`. Note that no server-side changes or coordination is required
since the two channels are entirely wire-compatible.

Reviewed By: strager

Differential Revision: D16173317

fbshipit-source-id: d9d7333bc7d33b8f2c386989b0b72daa601cd5b1

facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman