Avoid leaking AssetFileDescriptor.

Change-Id: Iac388c8aefc684980cb4c7131fb47319f6073eb3

java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java

@@ -95,8 +95,16 @@ final class BinaryDictionaryGetter {
                     + fallbackResId);
             return null;
         }
+        try {
             return AssetFileAddress.makeFromFileNameAndOffset(
                     context.getApplicationInfo().sourceDir, afd.getStartOffset(), afd.getLength());
+        } finally {
+            try {
+                afd.close();
+            } catch (IOException e) {
+                // Ignored
+            }
+        }
     }
 
     private static final class DictPackSettings {