Start sync when receive m.call.invite.

CHANGES.md

@@ -17,6 +17,7 @@ Improvements 🙌:
 
 Bugfix 🐛:
  - Messages encrypted with no way to decrypt after SDK update from 0.18 to 1.0.0 (#2252)
+ - Incoming call continues to ring if call is answered on another device (#1921)
 
 Translations 🗣:
  -

vector/src/main/java/im/vector/app/features/call/WebRtcPeerConnectionManager.kt

@@ -702,6 +702,8 @@ class WebRtcPeerConnectionManager @Inject constructor(
         )
 
         callContext.offerSdp = callInviteContent.offer
+
+        currentSession?.startSync(true)
     }
 
     private fun createAnswer() {