Report hardware acceleration in default manifest

Qt applications require the "hardwareAccelerated" flag set on
some devices or Android versions. The symptoms that this was missing
was problems when handling orientation changes. When the target
SDK version is >= 14, it is true by default, but for lower versions
it is not. There is no reason to set this to false for a Qt
application, since we don't use any of the unsupported 2D drawing
operations in the documentation, so lets just set it to true for
all applications.

Task-number: QTBUG-35293
Change-Id: Ie131a52a2a3fc5a520d0c5dd5d64f79269e9b6b5
Reviewed-by: BogDan Vatra <bogdan@kde.org>