Add systemserverclasspath_fragment.

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

Bug: 180105615
Test: atest CtsClasspathsTestCases
Change-Id: Ie4732ee602983047859b29b939585a3f716d5bdc

apex/appsearch/Android.bp

@@ -25,9 +25,7 @@ apex {
     name: "com.android.appsearch",
     manifest: "apex_manifest.json",
     bootclasspath_fragments: ["com.android.appsearch-bootclasspath-fragment"],
-    java_libs: [
-        "service-appsearch",
-    ],
+    systemserverclasspath_fragments: ["com.android.appsearch-systemserverclasspath-fragment"],
     key: "com.android.appsearch.key",
     certificate: ":com.android.appsearch.certificate",
     updatable: false,
@@ -52,3 +50,10 @@ bootclasspath_fragment {
     contents: ["framework-appsearch"],
     apex_available: ["com.android.appsearch"],
 }
+
+// Encapsulate the contributions made by the com.android.appsearch to the systemserverclasspath.
+systemserverclasspath_fragment {
+    name: "com.android.appsearch-systemserverclasspath-fragment",
+    contents: ["service-appsearch"],
+    apex_available: ["com.android.appsearch"],
+}