Add default_visibility for soong modules

So that we don't get surprise usages.

Bug: 348717861
Test: m nothing
Change-Id: I47319a727092c1bd936cca88f5713ee977a48b48

android/Android.bp

@@ -155,4 +155,6 @@ bootstrap_go_package {
         "vintf_fragment_test.go",
         "visibility_test.go",
     ],
+    // Used by plugins
+    visibility: ["//visibility:public"],
 }

android/team_proto/Android.bp

@@ -40,4 +40,8 @@ python_library_host {
     proto: {
         canonical_path_from_root: false,
     },
+    visibility: [
+        "//build/soong:__subpackages__",
+        "//tools/asuite/team_build_scripts",
+    ],
 }