NNAPI Concurrent Query Management -- Implementation

The NNAPI requires requests on a model to be asynchronously
processed. This CL implements a basic Event that can later be used
to block the runtime thread until the asynchronous request has
completed.

The design document for NN API asynchronous behavior:
https://docs.google.com/a/google.com/document/d/1mO35KK3Mnr489ZftTDnKXXnXiYxk19jZ1C4DWOqaVB4/edit?usp=sharing

Bug: 63905942
Test: VtsHalNeuralnetworksV1_0TargetTest (32-bit, 64-bit) with sample driver enabled by cherry-pick
      frameworks/ml/nn/runtime/test with and without sample driver enabled
Change-Id: I97b1d4cbf189176fb3b21b2cc1af09dddaff18ab
10 files changed
tree: 8454eaa8d2752e6ca876174f00c0790f7292002c
  1. nn/
  2. Android.bp