Add an example for onPayloadReady and VM service

This adds a simple integer addition service to the testapk's binary. The
demo app tries connecting the VM service once onPayloadReady is
triggered. Users can see the VM service's output.

Bug: 195381416
Test: launch MicrodroidDemoApp
Test: atest MicrodroidHostTestCases
Change-Id: I346084d08f753772cc00aa4c052e0b9b41d460ce
diff --git a/tests/testapk/Android.bp b/tests/testapk/Android.bp
index f545f8e..0b0810f 100644
--- a/tests/testapk/Android.bp
+++ b/tests/testapk/Android.bp
@@ -19,8 +19,11 @@
     srcs: ["src/native/testbinary.cpp"],
     shared_libs: [
         "android.system.keystore2-V1-ndk",
+        "android.system.virtualmachineservice-ndk",
+        "com.android.microdroid.testservice-ndk",
         "libbase",
         "libbinder_ndk",
+        "libbinder_rpc_unstable",
         "MicrodroidTestNativeLibSub",
     ],
 }