Move key_blob.h in to include/keymaster, to export it.

Change-Id: If28db94840557e6ca3019b7bcf7b5f29f0ff6cf7
diff --git a/key_blob_test.cpp b/key_blob_test.cpp
index 28de5eb..275da8b 100644
--- a/key_blob_test.cpp
+++ b/key_blob_test.cpp
@@ -24,7 +24,7 @@
 #include <keymaster/google_keymaster_utils.h>
 #include <keymaster/keymaster_tags.h>
 
-#include "key_blob.h"
+#include <keymaster/key_blob.h>
 
 int main(int argc, char** argv) {
     ::testing::InitGoogleTest(&argc, argv);