Add setUserDataEnabled and setUserDataRoamingEnabled in CommandsInterface, RILJ and Proxy

This changes defined setUserDataEnabled and setUserDataRoamingEnabled
in CommandsInterface, and implemented in RILJ by calling the proxy
function added in RadioDataProxy.

Test: m
Bug: 389120182
FLAG: EXEMPT HAL interface change
Change-Id: Ie7be68ed0284080e49118c2cb1f3b1e7a39851c2