Add bootclasspath_fragment.

Note that the contents of the bootclasspath_fragment are added as
dependencies to an apex, so there is no need to duplicate them in
java_libs.

Bug: 180105615
Test: atest CtsClasspathsTestCases
Ignore-AOSP-First: multiple previous changes aren't cherry-picked yet
Change-Id: Ia19ed0d5e13676882239dd5a1456c97549119994

Tethering/apex/Android.bp

@@ -23,9 +23,10 @@ apex {
     compile_multilib: "both",
     updatable: true,
     min_sdk_version: "30",
+    bootclasspath_fragments: [
+        "com.android.tethering-bootclasspath-fragment",
+    ],
     java_libs: [
-        "framework-connectivity",
-        "framework-tethering",
         "service-connectivity",
     ],
     multilib: {
@@ -61,6 +62,16 @@ android_app_certificate {
     certificate: "com.android.tethering",
 }
 
+// Encapsulate the contributions made by the com.android.tethering to the bootclasspath.
+bootclasspath_fragment {
+    name: "com.android.tethering-bootclasspath-fragment",
+    contents: [
+        "framework-connectivity",
+        "framework-tethering",
+    ],
+    apex_available: ["com.android.tethering"],
+}
+
 override_apex {
     name: "com.android.tethering.inprocess",
     base: "com.android.tethering",