InitAdminUser: Don't assume the group ID of the Administrators group

When using a database configuration where auto-increment column values
are pre-allocated, it is possible that the "Administrators" group is
created with an ID other than "1". In this case, the created admin user
will not be added to the correct group, and will not have the correct
admin permissions.

Instead of hard-coding the group ID, get it from the database.

Bug: Issue 3698
Change-Id: Ie9b3f4f9166d03e91d58b2ec584c5ce47aa2021c
1 file changed