Fix context sharing on android

The context version doesn't match surface version on some
android platforms. Fix the issue by forcing context format 2.0
on ES2.

Change-Id: I973246352f2e51acf22e622bdec51ce6574612fd
Task-number: QTBUG-42455
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@theqtcompany.com>