Move shared packages to NetworkStack project

Both were already statically linked both in the NetworkStack module and
the framework, so this change only reorganizes the file locations.

It makes more sense to have the library files in the NetworkStack module
folder, as changes to these files will be released with the same cadence
as the module, not the framework.

Bug: 139106271
Test: built, flashed, WiFi working
Change-Id: Ifaa882b53d1084ef32db6b27d35b56eb226c468f

Tethering/Android.bp

@@ -20,12 +20,14 @@ java_defaults {
     srcs: [
         "src/**/*.java",
         ":framework-tethering-shared-srcs",
+        ":net-module-utils-srcs",
         ":services-tethering-shared-srcs",
         ":servicescore-tethering-src",
     ],
     static_libs: [
         "androidx.annotation_annotation",
         "netd_aidl_interface-java",
+        "netlink-client",
         "networkstack-aidl-interfaces-java",
         "android.hardware.tetheroffload.control-V1.0-java",
         "tethering-client",