Fix Jest test for unread indicator when app is reopened from background

This is a follow-up of #14520 / #15097, where we changed the app's
behavior to keep the unread indicator present after backgrounding
and reopening the app.

tests/ui/UnreadIndicatorsTest.js

@@ -441,7 +441,7 @@ describe('Unread Indicators', () => {
             expect(unreadIndicator).toHaveLength(0);
         }));
 
-    it('Clears the new line indicator when the user moves the App to the background', () => signInAndGetAppWithUnreadChat()
+    it('Keeps the new line indicator when the user moves the App to the background', () => signInAndGetAppWithUnreadChat()
         .then(() => {
             // Verify we are on the LHN and that the chat shows as unread in the LHN
             expect(isDrawerOpen()).toBe(true);
@@ -478,9 +478,9 @@ describe('Unread Indicators', () => {
             AppState.emitCurrentTestState('background');
             AppState.emitCurrentTestState('active');
 
-            // Verify the new line is cleared
+            // Verify the new line is still present
             unreadIndicator = screen.queryAllByLabelText('New message line indicator');
-            expect(unreadIndicator).toHaveLength(0);
+            expect(unreadIndicator).toHaveLength(1);
         }));
 
     it('Displays the correct chat message preview in the LHN when a comment is added then deleted', () => {