Calculate quantized convolution multiplier using double type.

NNAPI has been using the float type for quantized convolution multiplier
calculation, which was causing an occasional off-by-one differences for
convolution operation results between TFLite/CPU and NNAPI/CPU implementations.

Test: MLTS com.android.nn.benchmark.app.NNTest#testNNAPI[mobilenet_*_quant] error rates
Test: NeuralNetworksTest_static
Bug: 115377572
Change-Id: If0bb9ff7229f5b3864a69c66566a4e4008f94c37
7 files changed
tree: f7b70099ddb51c0df959c39225c10135efa3332e
  1. nn/
  2. .clang-format
  3. CleanSpec.mk
  4. OWNERS
  5. PREUPLOAD.cfg