Description of problem:
After run misc/maintenance/bin/migrate-mongo-app-descriptors.rb to move mongo data
to the new descriptor enabled format, found that alias info is missing in the output of rhc-domain-info.


Version-Release number of selected component (if applicable):
Old instance: devenv_stage_127
Update packages to devenv_1609

How reproducible:
Always

Steps to Reproduce:
1. Start a old instance (devenv_stage_127)
2. Create an app and add alias to this app
$ rhc-domain-info -p xx
Application Info
================
phptest
    Framework: php-5.3
     Creation: 2012-02-15T07:03:33-05:00
         UUID: 38f16df39f864a5e9d557f38f6ecde2c
      Git URL: ssh://38f16df39f864a5e9d557f38f6ecde2c.rhcloud.com/~/git/phptest.git/
   Public URL: http://phptest-jialiu.dev.rhcloud.com/
      Aliases: bar.foo.com

3. Log into instance, upgrade packages to the latest.
# yum update
4. Run misc/maintenance/bin/migrate-mongo-app-descriptors.rb to move mongo data
to the new descriptor enabled format.
5. Check app info again
$ rhc-domain-info -p xx
Application Info
================
phptest
    Framework: php-5.3
     Creation: 2012-02-15T07:03:33-05:00
         UUID: 38f16df39f864a5e9d557f38f6ecde2c
      Git URL: ssh://38f16df39f864a5e9d557f38f6ecde2c.rhcloud.com/~/git/phptest.git/
   Public URL: http://phptest-jialiu.dev.rhcloud.com/

 Embedded: 
      None


  
Actual results:
Alias info is missing in the output of rhc-domain-info after running migration script

Expected results:
Alias info should be there.

Additional info: