Introduce boolean flag to show/hide Location Scanning preference.

This introduce one new flag:
config_show_location_scanning

Which when set to false, will hide "Scanning" in Location preference.

Some OEMs may control Bluetooth/Wi-Fi scanning themselves, so they may
want to hide the page from users.

Bug: 62418710
Test: make RunSettingsRoboTests
ROBOTEST_FILTER=LocationScanningPreferenceControllerTest

Change-Id: I19f0020a2c94f70b3b7956529f57af098ccc79fd

tests/robotests/src/com/android/settings/location/LocationScanningPreferenceControllerTest.java

@@ -0,0 +1,60 @@
+/*
+ * 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.settings.location;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.spy;
+
+import android.content.Context;
+
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class LocationScanningPreferenceControllerTest {
+
+  private Context mContext;
+  private LocationScanningPreferenceController mController;
+
+  @Before
+  public void setUp() {
+    MockitoAnnotations.initMocks(this);
+    mContext = spy(RuntimeEnvironment.application.getApplicationContext());
+    mController = new LocationScanningPreferenceController(mContext);
+  }
+
+  @Test
+  public void testLocationScanning_byDefault_shouldBeShown() {
+    assertThat(mController.isAvailable()).isTrue();
+  }
+
+  @Test
+  @Config(qualifiers = "mcc999")
+  public void testLocationScanning_ifDisabled_shouldNotBeShown() {
+    assertThat(mController.isAvailable()).isFalse();
+  }
+}