Summary:
Support Android 6 direct share.
BUG:362266
BackgroundService is a SIngleton now. This should only be used if strictly necessary.
Test Plan: Pick a random app with a share button, look for device entries in Sharing options (might not be there because other sharing options have higher priority)
Reviewers: #kde_connect, albertvaka
Reviewed By: #kde_connect, albertvaka
Subscribers: albertvaka, #kde_connect
Tags: #kde_connect
Differential Revision: https://phabricator.kde.org/D6743
