On android, holding your phone in portrait is considered to be 90 degrees. This the convention that android is using:
landscape: 0 portrait: 90 reverse landscape: 180 reverse portrait: 270
I know this doesn't make sense for phones but it does for tablets and there is realy no difference between tablets and phones on android.
So the metadata in the file are correct. The actual problem is that your browser ignores them. See me question here