Merge "Move is_system_uid utility from netd.c to netd.h" into main am: fe0d0f6e33 am: f5e896d25c am: a7d1e7936c

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2808573

Change-Id: I95c1b2136dead6a4732c653887f7c278adb99bbf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>