Use Android Junit Runner for webview ui test

BUG=641594

Review-Url: https://codereview.chromium.org/2286883003
Cr-Commit-Position: refs/heads/master@{#416427}

android_webview/tools/automated_ui_tests/BUILD.gn

@@ -46,6 +46,7 @@ instrumentation_test_apk("webview_ui_test_app_test_apk") {
   deps = [
     ":webview_ui_test_app_apk_resources",
     ":webview_ui_test_app_java",
+    "//third_party/android_support_test_runner:runner_java",
     "//third_party/ub-uiautomator:ub_uiautomator_java",
   ]
   data_deps = [

android_webview/tools/automated_ui_tests/javatests/AndroidManifest.xml

@@ -19,7 +19,7 @@
         <uses-library android:name="android.test.runner" />
     </application>
 
-    <instrumentation android:name="android.test.InstrumentationTestRunner"
+    <instrumentation android:name="android.support.test.runner.AndroidJUnitRunner"
         android:targetPackage="org.chromium.webview_ui_test"
         android:label="Tests for org.chromium.webview_ui_test"/>
-</manifest>
\ No newline at end of file
+</manifest>