fix c++ format error

Author: cherylEnkidu

Firestore/core/src/api/query_snapshot.h

@@ -22,6 +22,7 @@
 #include <utility>
 #include <vector>
 
+#include <vector>
 #include "Firestore/core/src/api/api_fwd.h"
 #include "Firestore/core/src/api/document_change.h"
 #include "Firestore/core/src/api/document_snapshot.h"

Firestore/core/src/core/expressions_eval.cc

@@ -584,8 +584,8 @@ template <typename T>
 bool ProcessUtf8(const std::string& s,
                  T* result,
                  std::function<void(T*, uint32_t, absl::string_view)> func) {
-  int i = 0;
-  const int len = s.size();
+  size_t i = 0;
+  const size_t len = s.size();
   const unsigned char* data = reinterpret_cast<const unsigned char*>(s.data());
 
   while (i < len) {