Use canonical UniquePtr.h header

Change-Id: Iab1dc428c2330a07a5944a1cfbb25c8134b11950
diff --git a/keystore/keystore.cpp b/keystore/keystore.cpp
index c890537..23d51c4 100644
--- a/keystore/keystore.cpp
+++ b/keystore/keystore.cpp
@@ -44,8 +44,8 @@
 
 #include <keymaster/softkeymaster.h>
 
+#include <UniquePtr.h>
 #include <utils/String8.h>
-#include <utils/UniquePtr.h>
 #include <utils/Vector.h>
 
 #include <keystore/IKeystoreService.h>