Guard VK_GOOGLE_SAMPLER_FILTERING_PRECISION
Guard VK_GOOGLE_SAMPLER_FILTERING_PRECISION

... to disable the extension on Cuttlefish in order
to pass dEQP-VK.api.info.android#no_unknown_extensions
on Cuttlefish.

Bug: b/174028661
Test: cts -m CtsDeqpTestCases
Change-Id: I9af0194e724a738491f6820eb2ca8947ac202e5a
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/50688
Presubmit-Ready: Jason Macnak <76caa58940b8c6785e996f522e85b625ac7c7baa@google.com>
Reviewed-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Tested-by: Jason Macnak <76caa58940b8c6785e996f522e85b625ac7c7baa@google.com>

bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader