hello_xr: Update help to show verbose flag

Author: rpavlik

src/tests/hello_xr/main.cpp

@@ -11,7 +11,7 @@ void ShowHelp() {
     // TODO: Improve/update when things are more settled.
     Log::Write(Log::Level::Info,
                "HelloXr --graphics|-g <Graphics API> [--formfactor|-ff <Form factor>] [--viewconfig|-vc <View config>] "
-               "[--blendmode|-bm <Blend mode>] [--space|-s <Space>]");
+               "[--blendmode|-bm <Blend mode>] [--space|-s <Space>] [--verbose|-v]");
     Log::Write(Log::Level::Info, "Graphics APIs:            D3D11, D3D12, OpenGLES, OpenGL, Vulkan");
     Log::Write(Log::Level::Info, "Form factors:             Hmd, Handheld");
     Log::Write(Log::Level::Info, "View configurations:      Mono, Stereo");