Fix loadCompleted flag in MediaChunk implementations.

This flag was always set even if the load was canceled and not completed.

PiperOrigin-RevId: 315659262

library/core/src/main/java/com/google/android/exoplayer2/source/chunk/ContainerMediaChunk.java

@@ -138,7 +138,7 @@ public class ContainerMediaChunk extends BaseMediaChunk {
     } finally {
       Util.closeQuietly(dataSource);
     }
-    loadCompleted = true;
+    loadCompleted = !loadCanceled;
   }
 
   /**

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaChunk.java

@@ -349,7 +349,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
       if (!hasGapTag) {
         loadMedia();
       }
-      loadCompleted = true;
+      loadCompleted = !loadCanceled;
     }
   }