Split the utility parts out of DefaultConfig.h

So that the client side may use the utilities without introducing the
"default configs". "default configs" should only be visible to the
server, and the vehicle hal server will take care of configs.

Test: build and unit tests

Bug: 188005769

Change-Id: If418dcdd1c5b261179104bb414c52f3eb04d3ea8
2 files changed