Add validation tests for NNAPI Burst serialized format

This CL adds the following two types of validation tests on the NNAPI
Burst serialized format:
(1) it directly modifies the serialized data (invalidating it) to ensure
    that vendor  driver services properly validates the serialized
    request
(2) it ensures that vendor driver services properly fail when the result
    channel is not large enough to return the data

This CL additionally includes miscellaneous cleanups:
(1) having a generic "validateEverything" function
(2) moving the "prepareModel" function that's common across
    validateRequest and validateBurst to a common area

Fixes: 129779280
Bug: 129157135
Test: mma
Test: VtsHalNeuralnetworksV1_2TargetTest (with sample-all)
Change-Id: Ib90fe7f662824de17db5a254a8c501855e45f6bd