validate_val() calls len() to check the value against allow_len,
min_len and max_len. len() requires the object to have a __len__()
method, which integers do not — calling len() on an int raises
TypeError.
Fix this by checking for __len__ first: if present, use len(val) as
usual; otherwise fall back to len(str(val)), which gives the number
of decimal digits for integer values.
Change-Id: Ibe91722ed1477b00d20ef5e4e7abd9068ff2f3e4
Jenkins: skip-card-test
Neels Hofmeyr
c5e7e59928