Step 30-A Constize gesture

Change-Id: I6c0b89d96532dc1c8ca71bb730ba22de5592ec67
diff --git a/native/jni/src/dictionary.cpp b/native/jni/src/dictionary.cpp
index 158c3fb..8ce8c8b 100644
--- a/native/jni/src/dictionary.cpp
+++ b/native/jni/src/dictionary.cpp
@@ -60,7 +60,7 @@
         int *codes, int codesSize, int *prevWordChars,
         int prevWordLength, int commitPoint, bool isGesture,
         bool useFullEditDistance, unsigned short *outWords,
-        int *frequencies, int *spaceIndices, int *outputTypes) {
+        int *frequencies, int *spaceIndices, int *outputTypes) const {
     int result = 0;
     if (isGesture) {
         DicTraverseWrapper::initDicTraverseSession(