Update use of media_dir following change in Libervia Media:

Libervia Media is now a Python package instead of files to put in a directory to specify
in settings. The discovery is now automatic, removing the need for settings and enabling
easier installation. Furthermore, it should now work even if the package is zipped.
`libervia_media` can now be specified as a dependency for frontends requiring it.

libervia/backend/plugins/plugin_misc_android.py

@@ -18,7 +18,6 @@ import sys
 import os
 import os.path
 import json
-from pathlib import Path
 from zope.interface import implementer
 from twisted.names import client as dns_client
 from twisted.python.procutils import which
@@ -28,13 +27,12 @@ from twisted.internet import protocol
 from twisted.internet import abstract
 from twisted.internet import error as int_error
 from twisted.internet import _sslverify
-from libervia.backend import G
 from libervia.backend.core.i18n import _, D_
 from libervia.backend.core.constants import Const as C
 from libervia.backend.core.log import getLogger
-from libervia.backend.core import exceptions
 from libervia.backend.tools.common import async_process
 from libervia.backend.memory import params
+from libervia import media
 
 
 log = getLogger(__name__)
@@ -283,8 +281,7 @@ class AndroidPlugin(object):
         self.am = activity.getSystemService(Context.AUDIO_SERVICE)
 
         # sound notification
-        media_dir = G.config.common.media_dir
-        assert media_dir is not None
+        media_dir = media.get_path()
         notif_path = media_dir / "sounds" / "notifications" / "music-box.mp3"
         self.notif_player = MediaPlayer()
         self.notif_player.setDataSource(str(notif_path))