[droidadec] Add mpeg audio version 2 support. Fixes JB#30199
[droidadec] Add mpeg audio version 2 support. Fixes JB#30199

We are reusing the mpeg4 audio infrastructure for mpeg2 and seems to work fine

mlehtima/gst-droid,mlehtima/gst-droid,sailfishos/gst-droid