Every now and then we get questions on why our examples (or custom user code) isn't receiving any updates and in many of these cases it turns of that the allowed_updates were not configured correctly. To avoid these problems at least with our examples, we should explicitly pass allowed_updates=Update.ALL_TYPES to run_polling, get_updates, run_webhook and set_webhook in our examples.

A PR that addresses this would be very welcome. It should cover all examples.