Rename KEY_VOICE_PRIVACY_DISABLE_BOOL -> KEY_VOICE_PRIVACY_DISABLE_UI_BOOL

Disabling voice privacy sounds scary. Update this config variable name
to what it actually does, which is to hide some settings UI.

Bug: 21571894
Change-Id: I165f9e91cee6b7c7572d8540d63519f1454ece9e
diff --git a/src/com/android/phone/CallFeaturesSetting.java b/src/com/android/phone/CallFeaturesSetting.java
index d3d9dcf..a083b7f 100644
--- a/src/com/android/phone/CallFeaturesSetting.java
+++ b/src/com/android/phone/CallFeaturesSetting.java
@@ -243,7 +243,7 @@
                     prefSet.removePreference(fdnButton);
 
                     if (!carrierConfig.getBoolean(
-                            CarrierConfigManager.KEY_VOICE_PRIVACY_DISABLE_BOOL)) {
+                            CarrierConfigManager.KEY_VOICE_PRIVACY_DISABLE_UI_BOOL)) {
                         addPreferencesFromResource(R.xml.cdma_call_privacy);
                     }
                 } else if (phoneType == PhoneConstants.PHONE_TYPE_GSM) {