Add NNAPI specification and infrastructure for FL7. am: 2edfc467f1 am: 0ca4f1a02e am: 385745474d

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1858468

Change-Id: Ib542d9a4ffd54bb9281723e9f10545fb7821e71e