Add a settings to change the sound effect volume

Bug: 5345401
Bug: 5402541
Change-Id: I1e653573a3362160104b77388d6cbd1700424649
diff --git a/java/res/values/strings.xml b/java/res/values/strings.xml
index 8bc97f6..e00547a 100644
--- a/java/res/values/strings.xml
+++ b/java/res/values/strings.xml
@@ -342,6 +342,8 @@
 
     <!-- Title of an option for usability study mode -->
     <string name="prefs_usability_study_mode">Usability study mode</string>
-    <!-- Title of the settings for vibration duration -->
-    <string name="prefs_vibration_duration_settings">Vibration duration settings</string>
+    <!-- Title of the settings for keypress vibration duration -->
+    <string name="prefs_keypress_vibration_duration_settings">Keypress vibration duration settings</string>
+    <!-- Title of the settings for keypress sound volume -->
+    <string name="prefs_keypress_sound_volume_settings">Keypress sound volume settings</string>
 </resources>