Adjust booleans in system modules (#5153)

* Adjust booleans in system modules.

* Fix some IP addresses

Co-authored-by: Sandra McCann <samccann@redhat.com>

Co-authored-by: Sandra McCann <samccann@redhat.com>

plugins/modules/system/interfaces_file.py

@@ -48,7 +48,7 @@ options:
       - Create a backup file including the timestamp information so you can get
         the original file back if you somehow clobbered it incorrectly.
     type: bool
-    default: 'no'
+    default: false
   state:
     type: str
     description:
@@ -136,7 +136,7 @@ EXAMPLES = '''
     iface: eth1
     option: mtu
     value: 8000
-    backup: yes
+    backup: true
     state: present
   register: eth1_cfg
 '''