Cleanup shims usage in Tethering

Now that S has gone to AOSP, this dependency is no longer
needed. It is, on the contrary, harmful as it prevents us
from adding shims that depend on T APIs in AOSP.

Test: builds
Change-Id: I64f0f394e826e58a9b7e772043bb6008428892e6
diff --git a/Tethering/Android.bp b/Tethering/Android.bp
index 495c9d7..60c1f2b 100644
--- a/Tethering/Android.bp
+++ b/Tethering/Android.bp
@@ -41,7 +41,6 @@
         "net-utils-device-common",
         "net-utils-device-common-netlink",
         "netd-client",
-        "NetworkStackApiCurrentShims",
     ],
     libs: [
         "framework-connectivity",