pw_kvs/pw_minimal_cpp_stdlib: Add missing includes

Add missing type_traits include to utility.h and key_value_store.h.

Change-Id: I7133497828630bfb53e2c258253d23502ca7de40
diff --git a/pw_kvs/public/pw_kvs/key_value_store.h b/pw_kvs/public/pw_kvs/key_value_store.h
index 749af8d..e2777dc 100644
--- a/pw_kvs/public/pw_kvs/key_value_store.h
+++ b/pw_kvs/public/pw_kvs/key_value_store.h
@@ -17,6 +17,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <string_view>
+#include <type_traits>
 
 #include "pw_containers/vector.h"
 #include "pw_kvs/checksum.h"
diff --git a/pw_minimal_cpp_stdlib/public/internal/utility.h b/pw_minimal_cpp_stdlib/public/internal/utility.h
index a58d9ce..ccfdf69 100644
--- a/pw_minimal_cpp_stdlib/public/internal/utility.h
+++ b/pw_minimal_cpp_stdlib/public/internal/utility.h
@@ -13,6 +13,8 @@
 // the License.
 #pragma once
 
+#include <type_traits>
+
 namespace std {
 
 template <typename T>