Make use of the single configuration point for the default shells

For now all the default shells of users and admin are hardcoded in
different parts of the project. This makes it impossible to run the
test suite against the setup, which has the default shell differed
from '/bin/sh'.

The single configuration point for the shell of users and admin is
added to overcome this limitation.

Fixes: https://pagure.io/freeipa/issue/7978
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Christian Heimes <cheimes@redhat.com>

ipaplatform/base/constants.py

@@ -10,6 +10,8 @@ import sys
 
 class BaseConstantsNamespace:
     IS_64BITS = sys.maxsize > 2 ** 32
+    DEFAULT_ADMIN_SHELL = '/bin/bash'
+    DEFAULT_SHELL = '/bin/sh'
     DS_USER = 'dirsrv'
     DS_GROUP = 'dirsrv'
     HTTPD_USER = "apache"

ipaplatform/base/paths.py

@@ -25,12 +25,10 @@ import os
 
 
 class BasePathNamespace:
-    BASH = "/bin/bash"
     BIN_HOSTNAMECTL = "/bin/hostnamectl"
     ECHO = "/bin/echo"
     GZIP = "/bin/gzip"
     LS = "/bin/ls"
-    SH = "/bin/sh"
     SYSTEMCTL = "/bin/systemctl"
     SYSTEMD_DETECT_VIRT = "/usr/bin/systemd-detect-virt"
     TAR = "/bin/tar"