Modify the AssetBundler to correctly identify the Gems that are enabled in the current active project (#5072)

* Modify the AssetBundler to correctly identify the Gems that are enabled in the current active project

Signed-off-by: Tommy Walton <waltont@amazon.com>

* Removed unnecessary if() statement and updated the comment.

Signed-off-by: Tommy Walton <waltont@amazon.com>

* Disabling gem loading in the asset bundler tests, just like the asset bundler itself.

Signed-off-by: Tommy Walton <waltont@amazon.com>

Code/Tools/AssetBundler/CMakeLists.txt

@@ -47,6 +47,10 @@ ly_add_target(
             AZ::AssetBundlerBatch.Static
 )
 
+# Adds a specialized .setreg to identify gems enabled in the active project.
+# This associates the AssetBundlerBatch target with the .Builders gem variants.
+ly_set_gem_variant_to_load(TARGETS AssetBundlerBatch VARIANTS Builders)
+
 # AssetBundler - Qt GUI Application
 ly_add_target(
     NAME AssetBundler ${PAL_TRAIT_BUILD_ASSETBUNDLER_APPLICATION_TYPE}
@@ -73,6 +77,10 @@ ly_add_target(
             ${additional_dependencies}
 )
 
+# Adds a specialized .setreg to identify gems enabled in the active project.
+# This associates the AssetBundler target with the .Builders gem variants.
+ly_set_gem_variant_to_load(TARGETS AssetBundler VARIANTS Builders)
+
 if(PAL_TRAIT_BUILD_TESTS_SUPPORTED)
 
     ly_add_target(

Code/Tools/AssetBundler/source/utils/applicationManager.cpp

@@ -54,7 +54,12 @@ namespace AssetBundler
     bool ApplicationManager::Init()
     {
         AZ::Debug::TraceMessageBus::Handler::BusConnect();
-        Start(AzFramework::Application::Descriptor());
+
+        ComponentApplication::StartupParameters startupParameters;
+        // The AssetBundler does not need to load gems
+        startupParameters.m_loadDynamicModules = false;
+        Start(AzFramework::Application::Descriptor(), startupParameters);
+
         AZ::SerializeContext* context;
         EBUS_EVENT_RESULT(context, AZ::ComponentApplicationBus, GetSerializeContext);
         AZ_Assert(context, "No serialize context");

Code/Tools/AssetBundler/tests/applicationManagerTests.cpp

@@ -71,7 +71,11 @@ namespace AssetBundler
 
 
             m_data->m_applicationManager.reset(aznew MockApplicationManagerTest(0, 0));
-            m_data->m_applicationManager->Start(AzFramework::Application::Descriptor());
+
+            AZ::ComponentApplication::StartupParameters startupParameters;
+            // The AssetBundler does not need to load gems
+            startupParameters.m_loadDynamicModules = false;
+            m_data->m_applicationManager->Start(AzFramework::Application::Descriptor(), startupParameters);
 
             // Without this, the user settings component would attempt to save on finalize/shutdown. Since the file is
             // shared across the whole engine, if multiple tests are run in parallel, the saving could cause a crash