Update dEQP-VK and Cherry usage documentation
Update dEQP-VK and Cherry usage documentation

- Information about running OpenGL ES tests has been removed.
- Installing Android Studio is no longer necessary.
- Prefer a Debug build of dEQP-VK over Release.
- Mention use of the SWIFTSHADER_VULKAN_API_LIBRARY_INSTALL_PATH for
  simplifying DLL installation.

Bug: b/149486511
Bug: b/147516027
Change-Id: I2a1ef18129a2b7304a3baba05c77d964c281ebd7
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/62209
Tested-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Kokoro-Result: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Alexis Hétu <1c7141772178a7e80858c3db5052b328076f08f4@google.com>

google/swiftshader,google/swiftshader,google/swiftshader