Allow non-interactive mode for trup_call commands

Do not rely on root-console when transactional::trup_call command starts with -n parameter.
Switch to root-console in the beginning of transactional::process_reboot and back at the end.

lib/transactional.pm

@@ -74,6 +74,10 @@ sub process_reboot {
     $args{automated_rollback} //= 0;
     $args{expected_grub} //= 1;
 
+    # Switch to roo-console as we need VNC to check for grub and for login prompt
+    my $prev_console = current_console();
+    select_console 'root-console', await_console => 0;
+
     handle_first_grub if ($args{automated_rollback});
 
     if (is_microos || is_sle_micro && !is_s390x) {
@@ -102,6 +106,9 @@ sub process_reboot {
         select_console 'root-console';
         assert_script_run 'clear';
     }
+
+    # Switch to the previous console
+    ($prev_console) ? select_console($prev_console) : die('The $prev_console is not defined.');
 }
 
 # Reboot if there's a diff between the current FS and the new snapshot
@@ -172,8 +179,9 @@ sub trup_call {
                 die 'Abort dialog not shown' unless wait_serial('Abort');
                 send_key 'ret';
             }
-        }
-        else {
+        } elsif ($cmd =~ /^-n/) {
+            record_info 'non-interactive', 'The transactional-update command is in non-interactive mode';
+        } else {
             die "Confirmation dialog not shown";
         }
     }