Alpha.4 changes cause incompatibilities with PIXI

The change made [here](https://github.com/expo/browser-polyfill/commit/86be0fb6129f40e03c74fe44650fc37900a491ce#diff-3b2c2fccf8d61b9cc2cc4aa34526db74L41) causes PIXI to determine that a GL view cannot be used in their util.isWebGLSupported function which breaks expo-pixi. The second argument in the function was ignored initially but is now assumed to be a context which in PIXI's case it is not. This issue makes expo-pixi unusable with this package past alpha.3. I have locked the resolution of this package at alpha.3 which seems to have fixed my issue but this is not a solution I would like to keep.

I would submit a PR to fix it myself but I don't feel like I have the experience with this package and the packages it supports to make sure a solution I come up with wouldn't break another project.