More efficient and easy to understand yuv2buffer converter

[gordinmitya]

Sorry, I unintentionally closed #336, so here is updated version of it.

Part discussion of this code is in issue #277.
Documentation about approach, unit-tests, performance benchmarks + demo application are here https://github.com/gordinmitya/yuv2buf. This code is tested in several apps in production with both: Camera2 output and MediaCodec outputs.

I compared performance of previous and new code on my Mi 9t pro (Snapdragon 855): old 3.5-4.0ms, new 2.6-3.0ms.
Modified CameraActivity.kt was used for comparison.

Will be happy to answer questions, if any!

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[gordinmitya]

@googlebot I fixed it.