Fix new projects always being created with OpenGL

Only Vulkan is fully implemented for now, so OpenGL isn't available
in the project manager yet.

This also makes the rendering driver checks use lowercase names
everywhere for consistency.

platform/javascript/export/export_plugin.cpp

@@ -300,9 +300,9 @@ void EditorExportPlatformJavaScript::get_preset_features(const Ref<EditorExportP
 
 	if (p_preset->get("vram_texture_compression/for_mobile")) {
 		String driver = ProjectSettings::get_singleton()->get("rendering/driver/driver_name");
-		if (driver == "OpenGL3") {
+		if (driver == "opengl3") {
 			r_features->push_back("etc");
-		} else if (driver == "Vulkan") {
+		} else if (driver == "vulkan") {
 			// FIXME: Review if this is correct.
 			r_features->push_back("etc2");
 		}