EGLPreRotationSurfaceTest.ChangeRotationWithDraw
alternates between landscape and portrait orientations.
The last one needs to be portrait, since this is the default state
that other tests expect.
Since changing orientation takes 1 second, it's more efficient to do it
in this one place instead of before every test.

Bug: angleproject:5781
Change-Id: I63c2eeb77663ea7de6679385c9deb089b16e74f3
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2785433Reviewed-by: Ian Elliott <ianelliott@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>