New dict format, step 2

Move some methods around and make static some methods

Bug: 4392433
Change-Id: I2bbe98aec118a416d21d1e293638e1d324505b9b
diff --git a/native/src/bigram_dictionary.cpp b/native/src/bigram_dictionary.cpp
index 36761b8..4bc4365 100644
--- a/native/src/bigram_dictionary.cpp
+++ b/native/src/bigram_dictionary.cpp
@@ -111,8 +111,7 @@
     mMaxBigrams = maxBigrams;
 
     if (HAS_BIGRAM && IS_LATEST_DICT_VERSION) {
-        int pos = mParentDictionary->isValidWordRec(
-                DICTIONARY_HEADER_SIZE, prevWord, 0, prevWordLength);
+        int pos = mParentDictionary->isValidWord(prevWord, prevWordLength);
         if (DEBUG_DICT) {
             LOGI("Pos -> %d", pos);
         }