Let Element Call widget receive m.room.create (#12710)

* Let Element Call widget receive m.room.create

This allows the widget to check the room version without prompting the
user to grant that capability, so the widget can know about
version-specific auth rules (namely MSC3779).

* Test that call widgets get RoomCreate events

Author: AndrewFerr

src/stores/widgets/StopGapWidgetDriver.ts

@@ -172,6 +172,10 @@ export class StopGapWidgetDriver extends WidgetDriver {
             this.allowedCapabilities.add(
                 WidgetEventCapability.forStateEvent(EventDirection.Receive, "org.matrix.msc3401.call.member").raw,
             );
+            // for determining auth rules specific to the room version
+            this.allowedCapabilities.add(
+                WidgetEventCapability.forStateEvent(EventDirection.Receive, EventType.RoomCreate).raw,
+            );
 
             const sendRecvRoomEvents = ["io.element.call.encryption_keys"];
             for (const eventType of sendRecvRoomEvents) {

test/stores/widgets/StopGapWidgetDriver-test.ts

@@ -95,6 +95,7 @@ describe("StopGapWidgetDriver", () => {
             "org.matrix.msc2762.timeline:!1:example.org",
             "org.matrix.msc2762.send.event:org.matrix.rageshake_request",
             "org.matrix.msc2762.receive.event:org.matrix.rageshake_request",
+            "org.matrix.msc2762.receive.state_event:m.room.create",
             "org.matrix.msc2762.receive.state_event:m.room.member",
             "org.matrix.msc2762.receive.state_event:org.matrix.msc3401.call",
             "org.matrix.msc2762.send.state_event:org.matrix.msc3401.call.member#@alice:example.org",