Rename android/config.h to android/config-file.h

This is to avoid naming conflicts later when including
"config.h" in android/main.c to get the correct definition
of TARGET_X86 and other macros.

Change-Id: I4743bf207597721612386213208efe0c7e2f41c5
diff --git a/android/main-common.h b/android/main-common.h
index 0d184d5..523e441 100644
--- a/android/main-common.h
+++ b/android/main-common.h
@@ -15,7 +15,7 @@
 #include <stdint.h>
 #include "android/cmdline-option.h"
 #include "android/skin/keyset.h"
-#include "android/config.h"
+#include "android/config-file.h"
 #include "android/avd/hw-config.h"
 
 /* Common routines used by both android/main.c and android/main-ui.c */