Remove some direct test dependencies from core's build.gradle
Remove some direct test dependencies from core's build.gradle

These are transitively provided by testutil's build.gradle.

This makes the core module consistent with the others like ui, hls, dash

PiperOrigin-RevId: 285729566

stari4ek/ExoPlayer,androidx/media,ened/ExoPlayer,google/ExoPlayer,stari4ek/ExoPlayer,ened/ExoPlayer,google/ExoPlayer,stari4ek/ExoPlayer,amzn/exoplayer-amazon-port,google/ExoPlayer,androidx/media,androidx/media,ened/ExoPlayer,amzn/exoplayer-amazon-port,amzn/exoplayer-amazon-port