[Android] Add a few helper functions to EGLHelper.
Let's us check for extension support and OpenGL version.
[Android] Add support for sterescopy configuration.

This menu allows us to configure the stereoscopy video settings if the device supports it.
This menu is only enabled if the hardware supports everything needed to use the feature.
Merge pull request #1761 from Sonicadvance1/Android_stereoscopy

Adds stereoscopy configuration support to Android.