[LYN-4410] Back buttons should preserve selected gems (#1359)

Code/Tools/ProjectManager/Source/CreateProjectCtrl.cpp

@@ -77,6 +77,7 @@ namespace O3DE::ProjectManager
         return ProjectManagerScreen::CreateProject;
     }
 
+    // Called when pressing "Create New Project"
     void CreateProjectCtrl::NotifyCurrentScreen()
     {
         ScreenWidget* currentScreen = reinterpret_cast<ScreenWidget*>(m_stack->currentWidget());
@@ -84,6 +85,11 @@ namespace O3DE::ProjectManager
         {
             currentScreen->NotifyCurrentScreen();
         }
+
+        // Gather the gems from the project template. When we will have multiple project templates, we need to re-gather them
+        // on changing the template and let the user know that any further changes on top of the template will be lost.
+        QString projectTemplatePath = m_newProjectSettingsScreen->GetProjectTemplatePath();
+        m_gemCatalogScreen->ReinitForProject(projectTemplatePath + "/Template", /*isNewProject=*/true);
     }
 
     void CreateProjectCtrl::HandleBackButton()
@@ -151,9 +157,6 @@ namespace O3DE::ProjectManager
             {
                 m_stack->setCurrentIndex(m_stack->currentIndex() + 1);
 
-                QString projectTemplatePath = m_newProjectSettingsScreen->GetProjectTemplatePath();
-                m_gemCatalogScreen->ReinitForProject(projectTemplatePath + "/Template", /*isNewProject=*/true);
-
                 Update();
             }
             else

Code/Tools/ProjectManager/Source/UpdateProjectCtrl.cpp

@@ -89,17 +89,18 @@ namespace O3DE::ProjectManager
         return ProjectManagerScreen::UpdateProject;
     }
 
+    // Called when pressing "Edit Project Settings..."
     void UpdateProjectCtrl::NotifyCurrentScreen()
     {
         m_stack->setCurrentIndex(ScreenOrder::Settings);
         Update();
+
+        // Gather the available gems that will be shown in the gem catalog.
+        m_gemCatalogScreen->ReinitForProject(m_projectInfo.m_path, /*isNewProject=*/false);
     }
 
     void UpdateProjectCtrl::HandleGemsButton()
     {
-        // The next page is the gem catalog. Gather the available gems that will be shown in the gem catalog.
-        m_gemCatalogScreen->ReinitForProject(m_projectInfo.m_path, /*isNewProject=*/false);
-
         m_stack->setCurrentWidget(m_gemCatalogScreen);
         Update();
     }