[fuchsia] Migrate MediaPlayerImpl to Natural FIDL bindings

Bug: 1351487
Change-Id: I877779bde54321dfaafd9a168be304a3a03c6287
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4361459


Reviewed-by: David Dorwin <ddorwin@chromium.org>
Commit-Queue: Bryant Chandler <bryantchandler@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1123189}