libnetdutils is referenced by netd.c and TrafficController.cpp, which
are going to be mainlined. Therefore, move libnetdutils to a common
place where both mainline module and platform code (Netd) can refer to.
Bug: 202086915
Test: build; flash; cd system/netd; atest
No-Typo-Check: Clean code move with no other changes.
BYPASS_INCLUSIVE_LANGUAGE_REASON=Clean code move with no other changes.
Merged-In: I645bfe35f6543149c9a9f894cd4158d27a481abe
Change-Id: I645bfe35f6543149c9a9f894cd4158d27a481abe
