Backport/2.5/37847Fix interfaces_file to accept allow-* (#37847 (#40008)

* Fix interfaces_file to accept allow-* (#37847)

(cherry picked from commit 5ac41ee8d8)

* interfaces-file

changelogs/fragments/interfaces_file-allow.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+- Fix interfaces_file to support `allow-` https://github.com/ansible/ansible/pull/37847

lib/ansible/modules/system/interfaces_file.py

@@ -225,7 +225,7 @@ def read_interfaces_lines(module, line_strings):
         elif words[0] == "auto":
             lines.append(lineDict(line))
             currently_processing = "NONE"
-        elif words[0] == "allow-":
+        elif words[0].startswith("allow-"):
             lines.append(lineDict(line))
             currently_processing = "NONE"
         elif words[0] == "no-auto-down":