Xfail the test_lockscreen tests due to awol touch events.
Merge pull request #284 from zacc/xfail_lockscreen_test

Xfail the test_lockscreen tests due to awol touch events.
ensures test will pass even if some items in the gallery are videos
changed to tap and other changes to make this one pass
Merge pull request #283 from ossreleasefeed/issue198-fix-gallery-if-first-is-video

ensures test will pass even if some items in the gallery are videos
Merge pull request #253 from ossreleasefeed/fix-test-wallpaper

changed to tap and other changes to make this one pass
Re-enable wallpaper test
Revert "Revert "Remove media between tests, and push resources to storage for tests that require them""

This reverts commit a3a0a99539d5f3e05a3c5fee156a614f145e9c6f.
Only instantiate the device manager the first time it's needed
Only instantiate the device manager if the target is running an Android build (not desktop builds)