Mobile Nerf sRGB and readme fix

[RodrigoHolztrattner-QuIC]

Description

Considering the MLP was trained with sRGB values and the Swapchain is SRGB, convert back to linear on shaders to prevent double linear->sRGB conversion.

Right image is with the fix, left is without it:

Also removes a readme line that was mistakenly added on original commit.

Fixes #

General Checklist:

Please ensure the following points are checked:

• My code follows the coding style
• I have reviewed file licenses
• I have commented any added functions (in line with Doxygen)
• I have commented any code that could be hard to understand
• My changes do not add any new compiler warnings
• My changes do not add any new validation layer errors or warnings
• I have used existing framework/helper functions where possible
• My changes do not add any regressions
• I have tested every sample to ensure everything runs correctly
• This PR describes the scope and expected impact of the changes I am making

Note: The Samples CI runs a number of checks including:

• I have updated the header Copyright to reflect the current year (CI build will fail if Copyright is out of date)
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Sample Checklist

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• I have tested the sample on at least one compliant Vulkan implementation
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[SaschaWillems]

Just a minor nitpick, but why not put the sRGB shader functions into a separate file and include instead of duplicating the same code for half a dozen shaders?

[RodrigoHolztrattner-QuIC]

@SaschaWillems with the include directive it works fine on Windows but on Android I would always get an error of type "'#include' : Could not process include directive for header name: xxxx".

For reference, what I did was to add "#extension GL_GOOGLE_include_directive: require" on each file that used the include, a shared .h file and ensure the include path was relative (as indicated by the extension spec). I also added all shader files to cmakelists.txt with SHADER_FILES_GLSL, but that didn't help either and it still fails on Android.

I also noticed a few of other samples that make usage of include directive fails to run on Android. At this point I'm not sure if these other samples fail due to my work environment or if there is indeed an issue with the framework/samples, but I will give it few more tries next week.

[gary-sweet]

It's a shame the shader code can't be common but it works, so +1 from me.