Testconfig: Adding some release branches to CI

Adding QtAndroidExtras, QtWinExtras and QtMacExtras release
branches into CI. Initial configurations will be identical
with stable branches, while the initial run will be exact copy
of it.

Change-Id: I2bcf62c00b03423322dd3208cf081bae70057a28
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>