Auto resume play when resources are available. Resource acquire optimization.

FIX 1: Removed resource release in handleResourcesLost for auto resume to work.

ResourceSet has AutoRelease false by default. Thus resources are automatically re-gained when they are available. To auto resume play after the preempting application has released its resources resources should not be released when they are lost.


FIX 2: Prevent resource acquire if acquire request is ongoing

ResourcePolicyImpl::acquire() is called twice when starting to play media file.
1st in QGstreamerPlayerControl::setMedia(const QMediaContent &content, QIODevice *stream)
    if (!content.isNull() || stream) {
        if (!m_resources->isGranted())
            m_resources->acquire();
2nd in QGstreamerPlayerControl::playOrPause(QMediaPlayer::State newState) as resources for the 1st acquire has not yet been granted when coming to this code
    if (!m_resources->isGranted())
        m_resources->acquire();