Embedded webviews were the easiest parental control bypass on Windows since about Windows 98. I've played so many flash games through the documentation for Microsoft Word!
I can't find any information anywhere that either confirms or denies the possibility to bypass Google's restrictions with web views. I assume it's possible, because it's possible on most platforms, but I suppose it depends on the implementation.
I've seen parental controls that employ an (on-device) MitM proxy and DNS filtering to ensure safety, and those apps will prevent almost any app from displaying unwanted content.