NNAPI: Add execution preference to prepareModel (HAL)

A model can be prepared in different ways to optimize for different
use-cases. This CL propagates the execution preference across the HAL so
that the NN service can better fit the users needs.

Bug: 77864669
Test: mma
Test: NeuralNetworksTest_static
Test: VtsHalNeuralnetworksV1_1TargetTest
Merged-In: Ib928d510d462f36b6a87d5e81010513db7829fa8
Change-Id: Ib928d510d462f36b6a87d5e81010513db7829fa8
(cherry picked from commit 2504c2fe)