Depend on SettingsLib's version of lifecycle and FooterMixin.

The implementations have been imported into SettingsLib. Setting's copy
can now be removed, which this change also does.

Test: Manually check battery status, which uses FooterMixin, looks OK.
make RunSettingsLibRobotTests && make RunSettingsRoboTests
     && make RunSettingsGoogleRoboTests
Change-Id: I6539605fdad80d156ff5ff249e68df4a1c412067

src/com/android/settings/utils/ThreadUtils.java

@@ -1,42 +0,0 @@
-/*
- * Copyright (C) 2016 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.
- */
-package com.android.settings.utils;
-
-import android.os.Looper;
-
-public class ThreadUtils {
-    private static volatile Thread sMainThread;
-
-    /**
-     * Returns true if the current thread is the UI thread.
-     */
-    public static boolean isMainThread() {
-        if (sMainThread == null) {
-            sMainThread = Looper.getMainLooper().getThread();
-        }
-        return Thread.currentThread() == sMainThread;
-    }
-
-    /**
-     * Checks that the current thread is the UI thread. Otherwise throws an exception.
-     */
-    public static void ensureMainThread() {
-        if (!isMainThread()) {
-            throw new RuntimeException("Must be called on the UI thread");
-        }
-    }
-
-}