Revert "Make MediaParser depend on the latest Exo version"

Revert "Update cts to depend on new ExoPlayer version"

Revert submission 16527581-update_exoplayer_version

Reason for revert: b/213856810
Reverted Changes:
I231cf3512:Update cts to depend on new ExoPlayer version
I26f7159a7:Make MediaParser depend on the latest Exo version
Id69a309ce:Update MediaParser's ExoPlayer version

Change-Id: I84fbc379ec4868d1a81a3abcabb61ccaa919972c