Root user entry in /etc/shadow has undocumented "x" instead of "!!, ! or "*"

[huornlmj]

Describe the bug
Root user entry in /etc/shadow has undocumented "x" instead of "!!, ! or *". Note this is not the case in the ISO version. The ISO version has normal root:*:.

To Reproduce
Steps to reproduce the behavior:

1. Build image (not ISO)
2. Observe the following in the /etc/shadow file (numbers may differ)

root:x:20153:7:90:5:::

Expected behavior
/etc/shadow should have either !!, ! or * instead of the "x" for disabled or non-active users. The use of "x" is undocumented.

[zcobol]

@huornlmj it might not be documented, but x in the 2nd field is just an invalid hash and will prevent that username from login in.

[huornlmj]

@zcobol that's understood, but it's an anomaly resulting in undocumented behavior. Really the reason I logged this is because the ISO version uses *. Why would there be a difference between the source version of Azure Linux and the ISO version?