Make second stage init visible to microdroid

microdroid is the base image for on-device VMs. We will use Android
components (init, adbd, servicemanager, ...) on the VM as much as
possible.

Bug: 177630284
Test: m microdroid
Change-Id: I36890644baaaf8f441698411dd869ddb220734fb
diff --git a/init/Android.bp b/init/Android.bp
index cd295cf..06ecc59 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -233,6 +233,7 @@
             ],
         },
     },
+    visibility: ["//packages/modules/Virtualization/microdroid"],
 }
 
 // Tests