use correct default for notification silencing

src/utils/notifications.ts

@@ -51,5 +51,5 @@ export async function createLocalNotificationSettingsIfNeeded(cli: MatrixClient)
 export function localNotificationsAreSilenced(cli: MatrixClient): boolean {
     const eventType = getLocalNotificationAccountDataEventType(cli.deviceId);
     const event = cli.getAccountData(eventType);
-    return event?.getContent<LocalNotificationSettings>()?.is_silenced ?? true;
+    return event?.getContent<LocalNotificationSettings>()?.is_silenced ?? false;
 }

test/utils/notifications-test.ts

@@ -81,8 +81,8 @@ describe('notifications', () => {
     });
 
     describe('localNotificationsAreSilenced', () => {
-        it('defaults to true when no setting exists', () => {
-            expect(localNotificationsAreSilenced(mockClient)).toBeTruthy();
+        it('defaults to false when no setting exists', () => {
+            expect(localNotificationsAreSilenced(mockClient)).toBeFalsy();
         });
         it('checks the persisted value', () => {
             mockClient.setAccountData(accountDataEventKey, { is_silenced: true });