Add matrix_rtc_session config options + bump js-sdk (#2756)

* Add matrix_rtc_session config options
* Bump js-sdk

https://github.com/matrix-org/matrix-js-sdk/compare/6971e7bebaad643c233e5057da7a0d42441c0789...fcb69b16ad8d170c67ea844f83543d467bbd7707

Also brings in:

- https://github.com/matrix-org/matrix-js-sdk/pull/4342
- https://github.com/matrix-org/matrix-js-sdk/pull/4494

src/rtcSessionHelpers.ts

@@ -98,8 +98,9 @@ export async function enterRTCSession(
 
   // right now we assume everything is a room-scoped call
   const livekitAlias = rtcSession.room.roomId;
+  const { features, matrix_rtc_session: matrixRtcSessionConfig } = Config.get();
   const useDeviceSessionMemberEvents =
-    Config.get().features?.feature_use_device_session_member_events;
+    features?.feature_use_device_session_member_events;
   rtcSession.joinRoomSession(
     await makePreferredLivekitFoci(rtcSession, livekitAlias),
     makeActiveFocus(),
@@ -108,6 +109,11 @@ export async function enterRTCSession(
       ...(useDeviceSessionMemberEvents !== undefined && {
         useLegacyMemberEvents: !useDeviceSessionMemberEvents,
       }),
+      membershipServerSideExpiryTimeout:
+        matrixRtcSessionConfig?.membership_server_side_expiry_timeout,
+      membershipKeepAlivePeriod:
+        matrixRtcSessionConfig?.membership_keep_alive_period,
+      makeKeyDelay: matrixRtcSessionConfig?.key_rotation_on_leave_delay,
     },
   );
 }