Mark some aidl_interface modules as unstable

With b/152655547, all aidl_interface modules are considered as stable
unless it is explicitly with "unstable: true". This change marks the
aidl_interface that are not used across updatable module bounraries
as unstable, so that the build system does not run the API
dumping/checking on them.

Bug: 152655547
Test: m
Change-Id: Ib99b57fde95887d1725ef7a4bdd3daf979aa059b
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index e6cfeb4..7298282 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -170,6 +170,7 @@
 
 aidl_interface {
     name: "libbinder_aidl_test_stub",
+    unstable: true,
     local_include_dir: "aidl",
     srcs: [":libbinder_aidl"],
     vendor_available: true,