Add TaplTestsQuickstep#testExcludeFromRecents

- Add ExcludeFromRecentsTestActivity, and add it to the manifest
  with excludeFromRecents="true"
- Add the test to check the current Overview task content
  description, ensuring that the excludeFromRecents task is
  present directly after a gesture but not after going home.
Bug: 324495241
Flag: None
Test: TaplTestsQuickstep#testExcludeFromRecents

Change-Id: I06be53673f0ac06924f79b44f19744da066cc7ea

quickstep/tests/src/com/android/launcher3/testcomponent/ExcludeFromRecentsTestActivity.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2024 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.testcomponent;
+
+/**
+ * Extension of BaseTestingActivity to help test excludeFromRecents="true".
+ */
+public class ExcludeFromRecentsTestActivity extends BaseTestingActivity {}