Videos in Timeline are not sized properly

[calren]

After some investigation:

• Setting the aspectRatio() is causing issues
• We are not handling landscape vs portrait videos separately (I think we need to)
• Not setting the aspectRatio() on the AndroidExternalSurface fixes the issue for portrait videos, but makes landscape videos look out of proportion
• I think we need to draw different sized backgrounds for portrait / landscape videos, otherwise there will be a lot of blank space for landscape videos

[calren]

This may be related to https://github.com/android/platform-samples/issues/172, which may be fixed in Media3 1.4.0-rc01