Fix intermittent localization package build errors on Linux

 * Work around what seems to be a race condition bug in Mono when waiting
   for child processes
 * Allow resgen output to go to stdout so error messages can be seen

(cherry picked from commit e752e1b0592c820bf41366022014f77a8964914a)

Change-Id: Iba6d1a8db9f09ad9f27d0624b0dc81a05ceb1248