Make apex availability of net-utils-framework-common explicit

This java library is available to the following
1. NetworkStack, a platform app
2. TetheringNext, an app in com.android.tethering

The availability to (2) was done implicitly using a baseline map in
build/soong/apex/apex.go. Make this explicit in Android.bp

Bug: 281077552
Test: m nothing
Change-Id: I5738ef1fc153e7ef9ccdde512e61310b0fd1ddbb
1 file changed