Allow autoplay unmuted for WebAPK in the manifest scope

chrome/android/java/templates/MonochromeApplication.template

Index: chrome/android/java/templates/MonochromeApplication.template
diff --git a/chrome/android/java/templates/MonochromeApplication.template b/chrome/android/java/templates/MonochromeApplication.template
index d721fbbab37984262b31019730ef02be9f43c13e..470c2d2f702c4c2a20910dc3cbaa6d65312a9d51 100644
--- a/chrome/android/java/templates/MonochromeApplication.template
+++ b/chrome/android/java/templates/MonochromeApplication.template
@@ -34,7 +34,8 @@ public class {{ monochrome_application_class }} extends {{ super_class }} {
         // ChildProcessCreationParams is only needed for browser process, though it is
         // created and set in all processes.
         mChildProcessCreationParams = new ChildProcessCreationParams(getPackageName(),
-                true /* isExternalService */, LibraryProcessType.PROCESS_CHILD);
+                true /* isExternalService */, LibraryProcessType.PROCESS_CHILD,
+                null /* additionalCommandLine */);
         ChildProcessCreationParams.set(mChildProcessCreationParams);
     }
 }