Fix computing the time it takes to render the first rooms

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift

@@ -138,6 +138,8 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
             return
         }
         
+        ServiceLocator.shared.analytics.signpost.beginFirstRooms()
+        
         // Combine together the state and the room list to correctly compute the view state if
         // data is present in the room list "cold cache"
         Publishers.CombineLatest(roomSummaryProvider.statePublisher,
@@ -162,6 +164,10 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
                     return
                 }
                 
+                if roomListMode == .rooms, self.state.roomListMode == .skeletons {
+                    ServiceLocator.shared.analytics.signpost.endFirstRooms()
+                }
+                
                 self.state.roomListMode = roomListMode
                 
                 MXLog.info("Received room summary provider update, setting view room list mode to \"\(self.state.roomListMode)\"")