Skeleton for IVmTethering service with flag guarding

This reverts commit f9676878292a49caa03e5270c3be2769b029db60.

Bug: 340376953
Test: adb shell /apex/com.android.virt/bin/vm run-microdroid --network-supported

Change-Id: I9c859dd43e7ba7c852a71afce8f36ca10477ad24
diff --git a/virtualizationservice/Android.bp b/virtualizationservice/Android.bp
index 0c39501..f9034af 100644
--- a/virtualizationservice/Android.bp
+++ b/virtualizationservice/Android.bp
@@ -30,6 +30,7 @@
         "android.system.virtualizationservice-rust",
         "android.system.virtualizationservice_internal-rust",
         "android.system.virtualmachineservice-rust",
+        "android.system.vmtethering-rust",
         "android.os.permissions_aidl-rust",
         "libandroid_logger",
         "libanyhow",