Rename android.media.MediaTranscodeManager -> MediaTranscodingManager am: 97423c97f3 am: 7fb6f652bd

Original change: https://googleplex-android-review.googlesource.com/c/platform/prebuilts/sdk/+/15521812

Change-Id: I8602cad590aaabf39729b8d0b41bff277c0b7f6a