Remove obsolete NFC unlock XML file.

NFC unlock was moved to TrustAgent. Fixes
build break.

Bug: 15538481
Change-Id: Iaf7f96a38ee36b80168cd92eef0d3b9748caa478
(cherry picked from commit 54a10a0a97a1aa8138d116078146741ec59da6fd)
diff --git a/res/xml/security_settings_nfc_unlock.xml b/res/xml/security_settings_nfc_unlock.xml
deleted file mode 100644
index 63e5a74..0000000
--- a/res/xml/security_settings_nfc_unlock.xml
+++ /dev/null
@@ -1,43 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright (C) 2013 The Android Open Source Project
-
-     Licensed under the Apache License, Version 2.0 (the "License");
-     you may not use this file except in compliance with the License.
-     You may obtain a copy of the License at
-
-          http://www.apache.org/licenses/LICENSE-2.0
-
-     Unless required by applicable law or agreed to in writing, software
-     distributed under the License is distributed on an "AS IS" BASIS,
-     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-     See the License for the specific language governing permissions and
-     limitations under the License.
--->
-
-<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
-
-    <PreferenceCategory
-            android:key="security_category"
-            android:title="@string/lock_settings_nfc_title">
-
-    <CheckBoxPreference
-            android:key="nfc_unlock_enabled"
-            android:title="@string/nfc_unlock_enabled"
-            android:persistent="false" />
-
-    <Preference
-            android:key="nfc_pairing"
-            android:title="@string/start_nfc_pairing"
-            android:persistent="false"
-            android:dependency="nfc_unlock_enabled" >
-            <intent android:action="android.settings.PAIR_NFC_DEVICE"/>
-    </Preference>
-
-    </PreferenceCategory>
-
-        <PreferenceCategory
-            android:key="nfc_unlock_tags_category"
-            android:title="@string/nfc_unlock_paired_tags_title">
-        </PreferenceCategory>
-
-</PreferenceScreen>