[Android] Test for VideosViewModel done

[Shivansh Saini]

vlc-android | branch: master | Shivansh Saini <shivanshs9 at gmail.com> | Wed Jul  3 18:10:41 2019 +0530| [f1339085696be71bceda9444a7a214030617e434] | committer: Geoffrey Métais

Test for VideosViewModel done

> https://code.videolan.org/videolan/vlc-android/commit/f1339085696be71bceda9444a7a214030617e434
---

 .../medialibrary/stubs/StubDataSource.java         |  10 +-
 vlc-android/build.gradle                           |   1 +
 .../vlc/viewmodels/browser/FilePickerModelTest.kt  |   3 +-
 .../vlc/viewmodels/mobile/VideosViewModelTest.kt   | 173 ++++++++++++++++++++-
 4 files changed, 180 insertions(+), 7 deletions(-)

Diff:   https://code.videolan.org/videolan/vlc-android/commit/f1339085696be71bceda9444a7a214030617e434