Simplify module visibility post build refactor

//visibility:override is no longer needed for impl_library_visibility
to override visibility.

Removing this allows the defaults module to specify better defaults.

- Stub libraries are made publicly visible, via `visibility`
- Impl libraries are private by default, but visibility is extended
  by the modules

Bug: 165017290
Test: m
Exempt-From-Owner-Approval: build refactor
Change-Id: Ibf35bfac5c99a21125f89ba10945f3364217b90f

Tethering/common/TetheringLib/Android.bp

@@ -16,19 +16,9 @@
 java_sdk_library {
     name: "framework-tethering",
     defaults: ["framework-module-defaults"],
+    impl_library_visibility: ["//frameworks/base/packages/Tethering:__subpackages__"],
 
-    // Allow access to the stubs from anywhere.
-    visibility: ["//visibility:public"],
-
-    // Restrict access to implementation library.
-    impl_library_visibility: [
-        "//visibility:override", // Ignore the visibility property.
-        "//frameworks/base/packages/Tethering:__subpackages__",
-    ],
-
-    srcs: [
-        ":framework-tethering-srcs",
-    ],
+    srcs: [":framework-tethering-srcs"],
 
     jarjar_rules: "jarjar-rules.txt",
     installable: true,