Adds symbolic min/max values for type enums.

This abstracts the boundary values for OperandType and
OperationType to avoid the need to update them in the
model validation functions.

Test: VtsHalNeuralnetworksV1_2TargetTest --hal_service_instance=android.hardware.neuralnetworks@1.2::IDevice/sample-all
Test: VtsHalNeuralnetworksV1_2CompatV1_1TargetTest --hal_service_instance=android.hardware.neuralnetworks@1.2::IDevice/sample-all
Test: VtsHalNeuralnetworksV1_2CompatV1_0TargetTest --hal_service_instance=android.hardware.neuralnetworks@1.2::IDevice/sample-all

Change-Id: I39155148d67215e32b4eb1991b885f65d5eeaca8
Merged-In: I39155148d67215e32b4eb1991b885f65d5eeaca8
(cherry-pick from c785d46e)