Cleanup VersionedIPreparedModel and PreparedModelCallback

This CL changes VersionedIPreparedModel to be synchronous. It returns
the results by value instead of requiring a callback be passed in.
Additionally, the IPreparedModel is wrapped in VersionedIPreparedModel
before being returned.

This CL additionally simplifies PreparedModelCallback by (1) decoupling
it from the base, (2) removing functions that are not used.

Bug: N/A
Test: mma
Test: atest NeuralNetworksTest_static
Test: atest VtsHalNeuralnetworksV1_0TargetTest (with sample-all)
Test: atest VtsHalNeuralnetworksV1_1TargetTest (with sample-all)
Test: atest VtsHalNeuralnetworksV1_2TargetTest (with sample-all)
Change-Id: Ic7587e0680ca7ccdc6cf429d9537396540ab3c0d
Merged-In: Ic7587e0680ca7ccdc6cf429d9537396540ab3c0d
(cherry picked from commit 7fe7acb7c286a0cf092b4ed01824b0da12f021fd)
6 files changed