Auto convert content shell tests to JUnit4

content/shell/android/javatests/src/org/chromium/content_shell_apk/ContentShellPreconditionsTest.java

-// Copyright 2017 The Chromium Authors. All rights reserved.
+// Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.content_shell_apk;
 
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.os.Build;
 import android.os.PowerManager;
 import android.support.test.InstrumentationRegistry;
@@ skipping 20 matching lines @@
         PowerManager pm = (PowerManager) InstrumentationRegistry.getContext().getSystemService(
                 Context.POWER_SERVICE);
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT_WATCH) {
             Assert.assertTrue("Many tests will fail if the screen is not on.", pm.isInteractive());
         } else {
             Assert.assertTrue("Many tests will fail if the screen is not on.", pm.isScreenOn());
         }
     }
 }