Move ShadowBluetoothUtils.java to tests/robotests/testutils.

This is to solve presubmit issue of ag/24820489

Bug: 296507968
Test: build
Change-Id: I44df560f30245ab4d98a3bedf40d9e5707e82189

tests/robotests/testutils/com/android/settings/testutils/shadow/ShadowBluetoothUtils.java

@@ -0,0 +1,44 @@
+/*
+ * 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.testutils.shadow;
+
+import android.content.Context;
+
+import com.android.settings.bluetooth.Utils;
+import com.android.settingslib.bluetooth.LocalBluetoothManager;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+import org.robolectric.annotation.Resetter;
+
+/** Robolectric shadow for the bluetooth utils. */
+@Implements(Utils.class)
+public class ShadowBluetoothUtils {
+
+    public static LocalBluetoothManager sLocalBluetoothManager;
+
+    @Implementation
+    protected static LocalBluetoothManager getLocalBtManager(Context context) {
+        return sLocalBluetoothManager;
+    }
+
+    /** Resets the local bluetooth manager to null. */
+    @Resetter
+    public static void reset() {
+        sLocalBluetoothManager = null;
+    }
+}