Remove duplicate test

I cloned the existing Instrumentation-based IntSetTest class
to be our first Robolectric test. Now Robolectric is working,
we can delete the Instrumentation test version.

Change-Id: I3adcfc451988a908c002b769b398348cb1782f1d

tests/src/com/android/launcher3/util/IntSetTest.java

@@ -1,58 +0,0 @@
-/*
- * Copyright (C) 2018 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.util;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import androidx.test.filters.SmallTest;
-import androidx.test.runner.AndroidJUnit4;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-/**
- * Unit tests for {@link IntSet}
- */
-@SmallTest
-@RunWith(AndroidJUnit4.class)
-public class IntSetTest {
-
-    @Test
-    public void testDuplicateEntries() {
-        IntSet set = new IntSet();
-
-        set.add(2);
-        assertEquals(1, set.size());
-
-        set.add(2);
-        assertEquals(1, set.size());
-        assertTrue(set.contains(2));
-        assertFalse(set.contains(1));
-
-        set.add(1);
-        assertEquals(2, set.size());
-        assertTrue(set.contains(2));
-        assertTrue(set.contains(1));
-
-
-        set.add(10);
-        assertEquals(3, set.size());
-
-        assertEquals("1, 2, 10", set.mArray.toConcatString());
-    }
-}