Revert "gn2bp: Remove `soong_namespace`"

Revert submission 2502135-remove_soong_namespace

Reason for revert: Missing line needs to be added

Reverted changes: /q/submissionid:2502135-remove_soong_namespace

Change-Id: I780a21cf7031e04eb368fda4f93ed16ea032ca8d
6 files changed