Add missing ANeuralNetworksOperandType.extraParams in ExecutionStep::addOperand

+ Moved code into anonymous namespace in ExecutionPlan
+ Removed unnecessary comment in CpuExecutor.h

Test for ExecutionStep::addOperand preserving extraParams
value will follow.

Bug: 121030521
Test: NeuralNetworksTest_static
Change-Id: I2bf17d9f3249c5376c314927be33196a80642dcc
2 files changed