Fix build error when androidxMediaModulePrefix is specified
Fix build error when androidxMediaModulePrefix is specified

When the media3 modules are referred from an external project and
gradle.ext.androidxMediaModulePrefix is specified, build error occurs
like the following.

> gradle.ext.androidxMediaModulePrefix = "media-"

> A problem occurred evaluating project ':media-lib-common'.
> > Project with path ':media-media-lib-cast' could not be found in project ':media-lib-common'.

As you can see, the build script of the common module is trying to
use an incorrect named project which has duplicated prefixes.

google/ExoPlayer,google/ExoPlayer,androidx/media,google/ExoPlayer,androidx/media,androidx/media