Have a collection of utilities for netd - NetdUtils

Some files which will be inside mainline module depend on
NetworkManagementService to talk to netd, but after they become
a part of mainline module, they cannot access @hide API of
NetworkManagementService.
So create a NetdUtils to help them to talk to netd.

Bug: 170598012
Test: atest CtsNetTestCasesLatestSdk NetdStaticLibTests
Change-Id: I8bee1204b9533b70844da0b3768427438fd0c890
diff --git a/staticlibs/client-libs/Android.bp b/staticlibs/client-libs/Android.bp
index f6d781c..e1a1086 100644
--- a/staticlibs/client-libs/Android.bp
+++ b/staticlibs/client-libs/Android.bp
@@ -9,7 +9,9 @@
     ],
     visibility: [
         "//packages/modules/Connectivity/Tethering",
-        "//frameworks/base/services:__subpackages__"
+        "//frameworks/base/services:__subpackages__",
+        "//frameworks/base/packages:__subpackages__",
+        "//frameworks/libs/net/client-libs/tests:__subpackages__",
     ],
     libs: ["androidx.annotation_annotation"],
     static_libs: [