integration test: raise the sync time before considering it as stable

It turns out that the failure came when using the known room path in the
room preview: Alice knows about the room, but for some reason the client
didn't retrieve all the state events from the sliding sync proxy yet.

Before, the sync would be considered stable after 2 seconds. This is too
little, considering that events come from the proxy that listens to
events from synapse. Raising this threshold to 15 seconds should help
getting all the room information from the proxy, and thus get all the
information we expected in the client.

testing/matrix-sdk-integration-testing/src/tests/sliding_sync/room.rs

@@ -1056,8 +1056,8 @@ async fn test_room_preview() -> Result<()> {
     let sliding_alice = alice
         .sliding_sync("main")?
         .with_all_extensions()
-        .poll_timeout(Duration::from_secs(5))
-        .network_timeout(Duration::from_secs(5))
+        .poll_timeout(Duration::from_secs(30))
+        .network_timeout(Duration::from_secs(30))
         .add_list(
             SlidingSyncList::builder("all")
                 .sync_mode(SlidingSyncMode::new_selective().add_range(0..=20)),
@@ -1103,8 +1103,11 @@ async fn test_room_preview() -> Result<()> {
     // successful updates for more than 2 seconds).
     let stream = sliding_alice.sync();
     pin_mut!(stream);
+
+    // Wait for updates coming in under than 15 seconds. After that, we consider the
+    // sync as stable.
     loop {
-        match timeout(Duration::from_secs(2), stream.next()).await {
+        match timeout(Duration::from_secs(15), stream.next()).await {
             Ok(None) | Err(_) => break,
             Ok(Some(up)) => {
                 warn!("alice got an update: {up:?}");
@@ -1118,6 +1121,7 @@ async fn test_room_preview() -> Result<()> {
     {
         // Dummy test for `Client::get_room_preview` which may call one or the other
         // methods.
+        info!("Alice gets a preview of the public room using any method");
         let preview = alice.get_room_preview(room_id.into(), Vec::new()).await.unwrap();
         assert_room_preview(&preview, &room_alias);
         assert_eq!(preview.state, Some(RoomState::Joined));
@@ -1145,18 +1149,21 @@ async fn get_room_preview_with_room_state(
     public_no_history_room_id: &RoomId,
 ) {
     // Alice has joined the room, so they get the full details.
+    info!("Alice gets a preview of the public room from state events");
     let preview = RoomPreview::from_state_events(alice, room_id).await.unwrap();
     assert_room_preview(&preview, room_alias);
     assert_eq!(preview.state, Some(RoomState::Joined));
 
     // Bob definitely doesn't know about the room, but they can get a preview of the
     // room too.
+    info!("Bob gets a preview of the public room from state events");
     let preview = RoomPreview::from_state_events(bob, room_id).await.unwrap();
     assert_room_preview(&preview, room_alias);
     assert!(preview.state.is_none());
 
     // Bob can't preview the second room, because its history visibility is neither
     // world-readable, nor have they joined the room before.
+    info!("Bob gets a preview of the private room from state events");
     let preview_result = RoomPreview::from_state_events(bob, public_no_history_room_id).await;
     assert_eq!(preview_result.unwrap_err().as_client_api_error().unwrap().status_code, 403);
 }
@@ -1169,6 +1176,7 @@ async fn get_room_preview_with_room_summary(
     public_no_history_room_id: &RoomId,
 ) {
     // Alice has joined the room, so they get the full details.
+    info!("Alice gets a preview of the public room from msc3266 using the room id");
     let preview =
         RoomPreview::from_room_summary(alice, room_id.to_owned(), room_id.into(), Vec::new())
             .await
@@ -1178,6 +1186,7 @@ async fn get_room_preview_with_room_summary(
     assert_eq!(preview.state, Some(RoomState::Joined));
 
     // The preview also works when using the room alias parameter.
+    info!("Alice gets a preview of the public room from msc3266 using the room alias");
     let full_alias = format!("#{room_alias}:{}", alice.user_id().unwrap().server_name());
     let preview = RoomPreview::from_room_summary(
         alice,
@@ -1193,6 +1202,7 @@ async fn get_room_preview_with_room_summary(
 
     // Bob definitely doesn't know about the room, but they can get a preview of the
     // room too.
+    info!("Bob gets a preview of the public room from msc3266 using the room id");
     let preview =
         RoomPreview::from_room_summary(bob, room_id.to_owned(), room_id.into(), Vec::new())
             .await
@@ -1202,6 +1212,7 @@ async fn get_room_preview_with_room_summary(
 
     // Bob can preview the second room with the room summary (because its join rule
     // is set to public, or because Alice is a member of that room).
+    info!("Bob gets a preview of the private room from msc3266 using the room id");
     let preview = RoomPreview::from_room_summary(
         bob,
         public_no_history_room_id.to_owned(),