init: create android::init:: namespace

With some small fixups along the way

Test: Boot bullhead
Test: init unit tests
Change-Id: I7beaa473cfa9397f845f810557d1631b4a462d6a
diff --git a/init/keychords.h b/init/keychords.h
index d2723b7..1c34098 100644
--- a/init/keychords.h
+++ b/init/keychords.h
@@ -17,9 +17,15 @@
 #ifndef _INIT_KEYCHORDS_H_
 #define _INIT_KEYCHORDS_H_
 
-struct service;
+#include "service.h"
 
-void add_service_keycodes(service*);
+namespace android {
+namespace init {
+
+void add_service_keycodes(Service* svc);
 void keychord_init();
 
+}  // namespace init
+}  // namespace android
+
 #endif