Limit build visibility of modules in apex/...

This changes the default visibility of soong modules in this directory
to __subpackages__, from the current public default.

This helps accidental dependencies sneaking in without intent from
the module owner.

Bug: 175604587
Test: m nothing
Exempt-From-Owner-Approval: cp
Merged-In: I1df8b8e087d27f62ce8c09d7e6e32d511efdba6b
Change-Id: I1df8b8e087d27f62ce8c09d7e6e32d511efdba6b
diff --git a/apex/permission/framework/Android.bp b/apex/permission/framework/Android.bp
index c0560f6..36b5dec 100644
--- a/apex/permission/framework/Android.bp
+++ b/apex/permission/framework/Android.bp
@@ -19,6 +19,7 @@
         "java/**/*.aidl",
     ],
     path: "java",
+    visibility: ["//frameworks/base"],
 }
 
 java_sdk_library {