Replace existing Robolectric test task with functioning one.

This CL does the following:
- Creates a dir for multivalentTests
- Creates symlinks for the dir to keep Android Studio happy
- Moves many files to the multivalentTests dir
- Adjusts gradle and soong build files to use the new dir as part of
their source sets.

Test: ./gradlew :NexusLauncher:testGoogleWithQuickstepDebugUnitTest
Test: atest Launcher3RoboTests
Fix: 316553886
Bug: 316553889
Flag: NA
Change-Id: Iae28fd0c0191b3ecf9bd2950800875950cca2622

tests/multivalentTests/src/com/android/launcher3/celllayout/ReorderTestCase.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2022 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.celllayout;
+
+import android.graphics.Point;
+
+import com.android.launcher3.celllayout.board.CellLayoutBoard;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class ReorderTestCase {
+    public List<CellLayoutBoard> mStart;
+    public Point moveMainTo;
+    public List<List<CellLayoutBoard>> mEnd;
+
+    public ReorderTestCase(List<CellLayoutBoard> start, Point moveMainTo,
+            List<CellLayoutBoard>... end) {
+        mStart = start;
+        this.moveMainTo = moveMainTo;
+        mEnd = Arrays.asList(end);
+    }
+
+    public ReorderTestCase(String start, Point moveMainTo, String ... end) {
+        mStart = CellLayoutBoard.boardListFromString(start);
+        this.moveMainTo = moveMainTo;
+        mEnd = Arrays
+                .asList(end)
+                .stream()
+                .map(CellLayoutBoard::boardListFromString)
+                .collect(Collectors.toList());
+    }
+}