Atom starter game ios fixes (#3297)

* Various fixes for AtomStarterGame on ios
 - Use low end pipeline on ioos by default for BoootStrapComponent
 - Track the need to bind null heap within Argument buffers
 - Only bind the null heap if its needed
 - Track its usage for Vertex/Fragment stages
 - Increase null dummy buffer to 1K to address GPU crash oon thee first frame

Signed-off-by: moudgils <moudgils@amazon.com>

Gems/Atom/Bootstrap/Code/Source/Platform/Windows/BootstrapSystemComponent_Traits_Platform.h

@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project.
+ * For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#define AZ_TRAIT_BOOTSTRAPSYSTEMCOMPONENT_PIPELINE_NAME     "passes/MainRenderPipeline.azasset"

Gems/Atom/Bootstrap/Code/Source/Platform/Windows/bootstrap_windows_files.cmake

@@ -0,0 +1,12 @@
+#
+# Copyright (c) Contributors to the Open 3D Engine Project.
+# For complete copyright and license terms please see the LICENSE at the root of this distribution.
+#
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+#
+#
+
+set(FILES
+    BootstrapSystemComponent_Traits_Platform.h
+)
+