Fix thumbnail sample hostnames to point to a hostname with a valid TLS cert

Created by: wilaw

The hostname "dash.edgesuite.net" does not have a valid TLS certificate when requested over https. A replacement hostname of "dash.akamaized.net" points at the same origin and has a valid certificate.

The thumbnail samples in the reference player implementation still refer to dash.edgesuite.net:

//dash.edgesuite.net/akamai/bbb_30fps/bbb_with_tiled_thumbnails.mpd //dash.edgesuite.net/akamai/bbb_30fps/bbb_with_4_tiles_thumbnails.mpd //dash.edgesuite.net/akamai/bbb_30fps/bbb_with_tiled_thumbnails_2.mpd //dash.edgesuite.net/akamai/bbb_30fps/bbb_with_multiple_tiled_thumbnails.mpd

These should be updated to point to "dash.akamaized.net"