Adds a method to check if there's an NNAPI accelerator available.

Bug: 141353636
Bug: 137150012

Test: CtsNNAPIBenchmarkTestCases

Change-Id: Ic0d066f29b1b0b4d10c7f9105dd342aca27408cf
Merged-In: Ic0d066f29b1b0b4d10c7f9105dd342aca27408cf
(cherry picked from commit 5e82b1b805a378504872e3724121c857c2eccc6b)
2 files changed