Stub out BackgroundApp/FastOverview states for Go.

Go's recents will not have swipe up to overview so there is no need to
have BackgroundAppState. We also do not support quickstep so we don't
need a distinct FastOverviewState. So we stub them out here.

Bug: 114136250
Test: Manual test Launcher3QuickstepGo + NexusLauncher
Change-Id: I9223cd35fc3c64688cda16dcaa1d5f40460c9323

go/quickstep/src/com/android/launcher3/uioverrides/BackgroundAppState.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2019 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.launcher3.uioverrides;
+
+/**
+ * State indicating that the Launcher is behind an app. Same as {@link OverviewState} for Go as we
+ * do not support swipe to overview or swipe to home.
+ */
+public final class BackgroundAppState extends OverviewState {
+    public BackgroundAppState(int id) {
+        super(id);
+    }
+}

go/quickstep/src/com/android/launcher3/uioverrides/FastOverviewState.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2019 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.launcher3.uioverrides;
+
+/**
+ * Extension of overview state used for QuickScrub. Same as {@link OverviewState} for Go as we do
+ * not support quickscrub.
+ */
+public final class FastOverviewState extends OverviewState {
+    public FastOverviewState(int id) {
+        super(id);
+    }
+}

go/quickstep/src/com/android/launcher3/uioverrides/OverviewState.java

@@ -33,9 +33,6 @@ import com.android.quickstep.RecentsModel;
  */
 public class OverviewState extends LauncherState {
 
-    // TODO: Remove this when we refactor BackgroundAppState
-    protected static final Rect sTempRect = new Rect();
-
     private static final int STATE_FLAGS = FLAG_WORKSPACE_ICONS_CAN_BE_DRAGGED
             | FLAG_DISABLE_RESTORE | FLAG_OVERVIEW_UI | FLAG_DISABLE_ACCESSIBILITY;