First part of an RPC mechanism for container <-> host communication

Mostly based on the protobuf based implementation from Mir.

android/service/main.cpp

@@ -15,6 +15,9 @@
  *
  */
 
+#include "android/service/daemon.h"
+
 int main(int, char**) {
-    return 0;
+    anbox::android::Daemon daemon;
+    return daemon.run();
 }