fix: AbstractMethodError with some integrations (#84) (#85)

Author: daytime-em

library/src/main/java/com/mux/stats/sdk/muxstats/MuxDataSdk.kt

@@ -246,6 +246,8 @@ abstract class MuxDataSdk<Player, PlayerView : View> @JvmOverloads protected con
     @Suppress("MemberVisibilityCanBePrivate")
     protected fun pxToDp(px: Int): Int = convertPxToDp(px, uiDelegate.displayDensity())
 
+    // Mux's SDKs set this dimension only during renditionchange so our impl here can return null
+    override fun getSourceCodec(): String? = null
     override fun getCurrentPosition(): Long = collector?.playbackPositionMills ?: 0L
     override fun getMimeType() = collector?.mimeType
     override fun getSourceWidth(): Int? = collector?.sourceWidth