This makes two fixes:
1. Remove `HlsSampleStreamWrapper.Callback` (package-private) from the
list of interfaces implemented by `HlsMediaPeriod` (`public`) and
move the implementation to a private inner class instead. This avoids
Metalava complaining about a public class that inherits from a
package-private type.
2. Reduce the visibility of
`RtpPayloadFormat.isFormatSupported(MediaDescription)` from `public`
to package-private. The `MediaDescription` type is already
package-private, so this method was already unusable outside the
package.
#minor-release
PiperOrigin-RevId: 487472781
(cherry picked from commit dbfc0cc7)
