Disable armnn nnapi backend

Discontinue maintenance and active support of ArmNN on Pixel phones.

Bug: 294459623
Test: Local nnapi_info
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:e33182147a0f24ed5c9fb0e9e3f3a11c83720cdd)
Merged-In: Idfa020dc46070764ccfff148b1fdfc72ccd16442
Change-Id: Idfa020dc46070764ccfff148b1fdfc72ccd16442
1 file changed