services/identity: Add Terms of Service to caveats page.
services/identity: Add Terms of Service to caveats page.

Change-Id: I7d545a4c8a5400ddd8b9228c3dd5718062318878

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