* Do not gather mem facts if command invalid (#40820)
* Do not gather mem facts if command invalid
In some firmwares, 'show memory statistics' fail, thus
do not populate mem if we got a failure after running that command.
* Fix pep8
* Warn if got error when running 'sh memory statistics'
* Fix pep8
(cherry picked from commit 669949e6a3)
* Update ios_facts.py (#40928)
Account for upper/lower case match occurrences of "[Nn]umber" and "[Ss]erial"
Model Number : WS-C3850-12X48U
System Serial Number : <removed>
(cherry picked from commit 12d221152b)
* Expand ios password prompt regex (#41131)
(cherry picked from commit 49fddb6f28)