Use unstable networkstack AIDLs in development branches

Development branches should use the -unstable version of the
NetworkStack AIDLs so that refreezing is not necessary for each
modification.
The versions will be re-frozen before each release instead.

Bug: 157534516
Change-Id: I74b4a16266bda7b8ac740b3a0193268da260fc2f
Test: m

Tethering/Android.bp

@@ -27,7 +27,8 @@ java_defaults {
         "androidx.annotation_annotation",
         "netd_aidl_interface-unstable-java",
         "netlink-client",
-        "networkstack-aidl-interfaces-java",
+        // TODO: use networkstack-client instead of just including the AIDL interface
+        "networkstack-aidl-interfaces-unstable-java",
         "android.hardware.tetheroffload.config-V1.0-java",
         "android.hardware.tetheroffload.control-V1.0-java",
         "net-utils-framework-common",