Flag all generated configs as non-default by default

The app is expected to flag a particular config themselves as default. This is primarily intended so that other parts of the app can determine what to do based on whether or not the config is a default config.

See https://github.com/vector-im/riot-web/issues/9290

src/utils/AutoDiscoveryUtils.js

@@ -26,6 +26,8 @@ export class ValidatedServerConfig {
 
     isUrl: string;
     identityEnabled: boolean;
+
+    isDefault: boolean;
 }
 
 export default class AutoDiscoveryUtils {
@@ -99,6 +101,7 @@ export default class AutoDiscoveryUtils {
             hsNameIsDifferent: url.hostname !== preferredHomeserverName,
             isUrl: preferredIdentityUrl,
             identityEnabled: !SdkConfig.get()['disable_identity_server'],
+            isDefault: false,
         });
     }
 }