Search bigrams for the lower case version of the word (A46)

...if there aren't any for the exact case version.

Bug: 6752830
Change-Id: I2737148b01ba04a64febe009ceb2ef53c265d224
diff --git a/native/jni/src/bigram_dictionary.h b/native/jni/src/bigram_dictionary.h
index 1ff1b2e..5372276 100644
--- a/native/jni/src/bigram_dictionary.h
+++ b/native/jni/src/bigram_dictionary.h
@@ -30,7 +30,8 @@
     BigramDictionary(const unsigned char *dict, int maxWordLength);
     int getBigrams(const int32_t *word, int length, int *inputCodes, int codesSize,
             unsigned short *outWords, int *frequencies, int maxWordLength, int maxBigrams) const;
-    int getBigramListPositionForWord(const int32_t *prevWord, const int prevWordLength) const;
+    int getBigramListPositionForWord(const int32_t *prevWord, const int prevWordLength,
+            const bool forceLowerCaseSearch) const;
     void fillBigramAddressToFrequencyMapAndFilter(const int32_t *prevWord, const int prevWordLength,
             std::map<int, int> *map, uint8_t *filter) const;
     bool isValidBigram(const int32_t *word1, int length1, const int32_t *word2, int length2) const;