Move subsampleOffset in Format

It's no longer text specific (it's used for metadata as well, and
in theory could apply to any stream in which samples contain multiple
sub-samples)

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=203767825

library/core/src/main/java/com/google/android/exoplayer2/Format.java

@@ -80,6 +80,13 @@ public final class Format implements Parcelable {
   /** DRM initialization data if the stream is protected, or null otherwise. */
   /** DRM initialization data if the stream is protected, or null otherwise. */
   public final @Nullable DrmInitData drmInitData;
   public final @Nullable DrmInitData drmInitData;
 
 
+  /**
+   * For samples that contain subsamples, this is an offset that should be added to subsample
+   * timestamps. A value of {@link #OFFSET_SAMPLE_RELATIVE} indicates that subsample timestamps are
+   * relative to the timestamps of their parent samples.
+   */
+  public final long subsampleOffsetUs;
+
   // Video specific.
   // Video specific.
 
 
   /**
   /**
@@ -141,15 +148,6 @@ public final class Format implements Parcelable {
    */
    */
   public final int encoderPadding;
   public final int encoderPadding;
 
 
-  // Text specific.
-
-  /**
-   * For samples that contain subsamples, this is an offset that should be added to subsample
-   * timestamps. A value of {@link #OFFSET_SAMPLE_RELATIVE} indicates that subsample timestamps are
-   * relative to the timestamps of their parent samples.
-   */
-  public final long subsampleOffsetUs;
-
   // Audio and text specific.
   // Audio and text specific.
 
 
   /**
   /**