Add missing OWNERS to frameworks/base/core/.../media

When some files were migrated from frameworks/base/media/.../media to frameworks/base/core/.../media, no OWNERS was added to cover them.

Therefore, move relevant parts of frameworks/base/media/.../media/OWNERS to frameworks/base/core/.../media/OWNERS to restore expected ownership

Flags: EXEMPT metadata change only
Test: OWNERS change only
Change-Id: I28e2970553cf86bdcf0866bc84cfc114220ded2a