/usr/lib/mozilla/plugins:
  => flashplugin-alternative.so
     - symlink to /etc/alternatives/mozilla-flashplugin
     - symlink to /usr/lib/flashplugin-installer/libflashplayer.so
        (size: 15053104 bytes, mtime: Thu Nov  8 11:43:37 2018)

/usr/lib/xulrunner-addons/plugins: