Use consistent case for sideloaded

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=176333544

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java

@@ -83,7 +83,7 @@ public final class DashMediaSource implements MediaSource {
      * @param chunkSourceFactory A factory for {@link DashChunkSource} instances.
      * @return A new builder.
      */
-    public static Builder forSideLoadedManifest(DashManifest manifest,
+    public static Builder forSideloadedManifest(DashManifest manifest,
         DashChunkSource.Factory chunkSourceFactory) {
       Assertions.checkArgument(!manifest.dynamic);
       return new Builder(manifest, null, null, chunkSourceFactory);