Add keyboard hypotenuse metric to ProximityInfo.

Change-Id: If4a23041b460326a579e8b8cab20b5c027441e23
diff --git a/native/jni/src/proximity_info.h b/native/jni/src/proximity_info.h
index d42c723..ee79367 100644
--- a/native/jni/src/proximity_info.h
+++ b/native/jni/src/proximity_info.h
@@ -62,6 +62,7 @@
     int getGridHeight() const { return GRID_HEIGHT; }
     int getKeyboardWidth() const { return KEYBOARD_WIDTH; }
     int getKeyboardHeight() const { return KEYBOARD_HEIGHT; }
+    float getKeyboardHypotenuse() const { return KEYBOARD_HYPOTENUSE; }
 
     int getKeyCenterXOfCodePointG(int charCode) const;
     int getKeyCenterYOfCodePointG(int charCode) const;
@@ -97,6 +98,7 @@
     const int KEY_COUNT;
     const int KEYBOARD_WIDTH;
     const int KEYBOARD_HEIGHT;
+    const float KEYBOARD_HYPOTENUSE;
     const bool HAS_TOUCH_POSITION_CORRECTION_DATA;
     char mLocaleStr[MAX_LOCALE_STRING_LENGTH];
     int *mProximityCharsArray;