Disable publishing block when media3 included in another build.

From https://github.com/androidx/media/pull/127/files

PiperOrigin-RevId: 485921271

settings.gradle

@@ -18,6 +18,8 @@ if (gradle.ext.has('exoplayerModulePrefix')) {
     modulePrefix += gradle.ext.exoplayerModulePrefix
     modulePrefix += gradle.ext.exoplayerModulePrefix
 }
 }
 
 
+rootProject.name = 'media3'
+
 include modulePrefix + 'demo'
 include modulePrefix + 'demo'
 project(modulePrefix + 'demo').projectDir = new File(rootDir, 'demos/main')
 project(modulePrefix + 'demo').projectDir = new File(rootDir, 'demos/main')
 include modulePrefix + 'demo-cast'
 include modulePrefix + 'demo-cast'