Migrate robolectric tests to junit tests

This change do the 2 things:

1. Add new junit tests files which replace robolectric
   RobolectricTestRunner & RuntimeEnvironment with
   AndroidX objects without problem.
2. Remove the robolectric test files which have it's new junit files.

This change migrate 103 files, there are still 1209
files to go.

Bug: 174728471
Test: atest
      make RunSettingsRoboTests
Change-Id: I15ed3f4745b85862f720aabbf710ce1475aced93

tests/unit/src/com/android/settings/widget/RtlCompatibleViewPagerTest.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2020 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.widget;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.os.Parcelable;
+import android.text.TextUtils;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.viewpager.widget.PagerAdapter;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.Locale;
+
+@RunWith(AndroidJUnit4.class)
+public class RtlCompatibleViewPagerTest {
+
+    private Locale mLocaleEn;
+    private Locale mLocaleHe;
+    private RtlCompatibleViewPager mViewPager;
+
+    @Before
+    public void setUp() {
+        mViewPager = new RtlCompatibleViewPager(ApplicationProvider.getApplicationContext());
+        mViewPager.setAdapter(new ViewPagerAdapter());
+        mLocaleEn = new Locale("en");
+        mLocaleHe = new Locale("he");
+    }
+
+    @Test
+    public void testGetCurrentItem_shouldMaintainIndexDuringLocaleChange() {
+        testRtlCompatibleInner(0);
+        testRtlCompatibleInner(1);
+    }
+
+    private void testRtlCompatibleInner(int currentItem) {
+        // Set up the environment
+        Locale.setDefault(mLocaleEn);
+        mViewPager.setCurrentItem(currentItem);
+
+        assertThat(TextUtils.getLayoutDirectionFromLocale(Locale.getDefault()))
+                .isEqualTo(View.LAYOUT_DIRECTION_LTR);
+        assertThat(mViewPager.getCurrentItem()).isEqualTo(currentItem);
+
+        // Simulate to change the language to RTL
+        Parcelable savedInstance = mViewPager.onSaveInstanceState();
+        Locale.setDefault(mLocaleHe);
+        mViewPager.onRestoreInstanceState(savedInstance);
+
+        assertThat(TextUtils.getLayoutDirectionFromLocale(Locale.getDefault()))
+                .isEqualTo(View.LAYOUT_DIRECTION_RTL);
+        assertThat(mViewPager.getCurrentItem()).isEqualTo(currentItem);
+    }
+
+    /**
+     * Test viewpager adapter, uses 2 view to test it
+     */
+    private static final class ViewPagerAdapter extends PagerAdapter {
+
+        private static final int ITEM_COUNT = 2;
+
+        private ViewPagerAdapter() {
+        }
+
+        @Override
+        public int getCount() {
+            return ITEM_COUNT;
+        }
+
+        @Override
+        public boolean isViewFromObject(View view, Object object) {
+            return view == object;
+        }
+
+        @Override
+        public Object instantiateItem(ViewGroup container, int position) {
+            return null;
+        }
+
+        @Override
+        public CharSequence getPageTitle(int position) {
+            return null;
+        }
+    }
+}