Fix mismatched attribute in KeyboardView

This is a followup of Iea7f8f34.

Bug: 5023981
Change-Id: Ice6d949581aea7ca68799be2b91ff28234dd88d6
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardView.java b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
index d6d0f5c..d6b7ed0 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
@@ -223,7 +223,7 @@
 
         public KeyDrawParams(TypedArray a) {
             mKeyBackground = a.getDrawable(R.styleable.KeyboardView_keyBackground);
-            if (a.hasValue(R.styleable.KeyboardView_keyLabelSize)) {
+            if (a.hasValue(R.styleable.KeyboardView_keyLetterSize)) {
                 mKeyLetterRatio = UNDEFINED_RATIO;
                 mKeyLetterSize = a.getDimensionPixelSize(
                         R.styleable.KeyboardView_keyLetterRatio, 0);