You can configure this in mysql configuration file
open /etc/my.cnf
file
In this file all the lines which is configuring the password policy make those commented like
#validate-password=FORCE_PLUS_PERMANENT
#validate_password_length=10
#validate_password_mixed_case_count=1
#validate_password_number_count=1
#validate_password_policy=MEDIUM
Uncomment and change the value of the properties you want to change.