Add missing header

std::sort is defined in <algorithm>

Change-Id: Ie523480d394b36d33a77307ba8e699846de680c3
diff --git a/HidlTypeAssertion.cpp b/HidlTypeAssertion.cpp
index 6e4822a..c684054 100644
--- a/HidlTypeAssertion.cpp
+++ b/HidlTypeAssertion.cpp
@@ -18,6 +18,7 @@
 
 #include <hidl-util/Formatter.h>
 
+#include <algorithm>
 #include <string>
 #include <vector>