[Android] Display a loading state in the playlist dialog + cleanup dead code

[Nicolas Pomepuy]

vlc-android | branch: master | Nicolas Pomepuy <nicolas at videolabs.io> | Mon Mar  9 10:17:29 2020 +0100| [840c9e97d75a385a05f425d52b42105f02942210] | committer: Geoffrey Métais

Display a loading state in the playlist dialog + cleanup dead code

> https://code.videolan.org/videolan/vlc-android/commit/840c9e97d75a385a05f425d52b42105f02942210
---

 .../main/java/org/videolan/resources/Constants.kt  |   2 +
 .../resources/src/main/res/values/strings.xml      |   4 +-
 .../vlc-android/res/layout/dialog_playlist.xml     | 205 ++++++++++++---------
 .../vlc/gui/browser/BaseBrowserFragment.kt         |  38 ++--
 .../org/videolan/vlc/gui/dialogs/ContextSheet.kt   |   3 +-
 .../videolan/vlc/gui/dialogs/SavePlaylistDialog.kt | 133 +++++++------
 .../src/org/videolan/vlc/gui/helpers/UiTools.kt    |  10 +-
 .../org/videolan/vlc/providers/BrowserProvider.kt  |   9 +-
 .../videolan/vlc/providers/FileBrowserProvider.kt  |   6 +-
 9 files changed, 237 insertions(+), 173 deletions(-)

Diff:   https://code.videolan.org/videolan/vlc-android/commit/840c9e97d75a385a05f425d52b42105f02942210