Move bigram reading methods to BigramListReadingUtils.

Bug: 6669677
Change-Id: Icb024a8af577323b4dcf74f4c4054cfb8b57a943
diff --git a/native/jni/Android.mk b/native/jni/Android.mk
index 4786ef6..ecc0e4c 100644
--- a/native/jni/Android.mk
+++ b/native/jni/Android.mk
@@ -71,6 +71,7 @@
     suggest/core/policy/weighting.cpp \
     suggest/core/session/dic_traverse_session.cpp \
     $(addprefix suggest/policyimpl/dictionary/, \
+        bigram/bigram_list_reading_utils.cpp \
         dictionary_structure_with_buffer_policy_factory.cpp \
         dynamic_patricia_trie_node_reader.cpp \
         dynamic_patricia_trie_policy.cpp \