Add PACK operation to NNAPI feature level 6.

Cherrypicked from Ic15d047b70c62437b4f0db6f2ca10127591ae07c

Bug: 200281183
Bug: 200280665

Test: m -j NeuralNetworksTest_static
Test: VtsHalNeuralnetworksTargetTest

Change-Id: Ic15d047b70c62437b4f0db6f2ca10127591ae07c
Merged-In: Ic15d047b70c62437b4f0db6f2ca10127591ae07c
2 files changed