Hide screenshare button in video rooms on Desktop (#9045)

* Hide screenshare button in video rooms on Desktop

* Fix tests

src/utils/WidgetUtils.ts

@@ -26,6 +26,7 @@ import { CallType } from "matrix-js-sdk/src/webrtc/call";
 import { randomString, randomLowercaseString, randomUppercaseString } from "matrix-js-sdk/src/randomstring";
 
 import { MatrixClientPeg } from '../MatrixClientPeg';
+import PlatformPeg from '../PlatformPeg';
 import SdkConfig from "../SdkConfig";
 import dis from '../dispatcher/dispatcher';
 import WidgetEchoStore from '../stores/WidgetEchoStore';
@@ -510,6 +511,7 @@ export default class WidgetUtils {
             'roomId=$matrix_room_id',
             'theme=$theme',
             'roomName=$roomName',
+            `supportsScreensharing=${PlatformPeg.get().supportsJitsiScreensharing()}`,
         ];
         if (opts.auth) {
             queryStringParts.push(`auth=${opts.auth}`);