For mpd codes, rename dash_packager to edash_packager; for media codes,
add namespace edash_packager.
Change-Id: I1120e6110c734cd02bdbe15f1cf7abddcdfdd7ea
These checks were disabled in Chromium due to historical reason.
Also fix compilation errors as a result of the above mentioned change.
Change-Id: I5d240f2f11aa5920598f954d696a15bdcbf78fd8