Remove hal::utils::countNumberOfConsumers

This CL removes hal::utils::countNumberOfConsumers and uses the existing
nn::countNumberOfConsumers.

This change is part of a larger chain of changes to remove HIDL and AIDL
libraries from neuralnetworks_utils_hal_common.

Bug: N/A
Test: mma
Change-Id: I7d06ea355eae7aa80b94b09a23d606bbb2322120