30/public/android.jar is exported as a filegroup

The new CTS test CtsUsesNativeLibraryTest needs to package the jar
library in the test. Defining the jar library as a filegroup was needed
otherwise the jar which is arch-agnostic can't be depended on from the
arch-specific test.

Bug: 142191088
Test: atest CtsUsesNativeLibraryTest
Change-Id: I8add919c0b96d2695b35c24bbf23badb83b5b89a
diff --git a/Android.bp b/Android.bp
index 4741c58..f15f730 100644
--- a/Android.bp
+++ b/Android.bp
@@ -89,6 +89,17 @@
     ],
 }
 
+// This filegroup is to package android.jar into CtsUsesNativeLibraryTestCase
+filegroup {
+    name: "sdk_public_30_android",
+    srcs: [
+        "30/public/android.jar",
+    ],
+    visibility: [
+        "//cts/hostsidetests/library",
+    ],
+}
+
 prebuilt_apis {
     name: "sdk",
     api_dirs: [