Wait for shader compilation to finish before rendering burn outs

We need to wait for shaders to compile before starting a level sequence capture. POssible other scenarios where this may be needed are:

When levels are streamed in
When content is made visible for the first time while the sequence is playing

Change a global shader
Render out a level sequence without compiling those shaders

Result: Movie is rendered out with uncompiled shaders
Expected: Movie is rendered out with compiled shaders