Add project ID to internal SIPCall info. (#1346)

* Add project ID to internal SIPCall info.

* generated protobuf

---------

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

Author: dennwc

.changeset/sip-proj-id.md

@@ -0,0 +1,6 @@
+---
+"@livekit/protocol": patch
+"github.com/livekit/protocol": patch
+---
+
+Add project ID to internal SIPCall info.

protobufs/rpc/io.proto

@@ -272,4 +272,5 @@ message SIPCall {
   livekit.SIPUri to = 5; // To header
   repeated livekit.SIPUri via = 6; // Via headers
   string sip_call_id = 7; // SIP protocol generated call ID
+  string project_id = 8; // LiveKit project ID (Cloud only)
 }