Fix 1 ErrorProneStyle finding:

* @Flags is not a TYPE_USE annotation, so should appear before any modifiers and after Javadocs.
  (see go/java-style#s4.8.5-annotations)

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#codehealth

PiperOrigin-RevId: 386849198

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/Mp4Extractor.java

@@ -133,7 +133,7 @@ public final class Mp4Extractor implements Extractor, SeekMap {
    */
   private static final long MAXIMUM_READ_AHEAD_BYTES_STREAM = 10 * 1024 * 1024;
 
-  private final @Flags int flags;
+  @Flags private final int flags;
 
   // Temporary arrays.
   private final ParsableByteArray nalStartCode;