Reduce severity of log messages in validation methods

I noticed this while reviewing Ic2c87174.  When I read through log
files, I don't want to see errors like this that come from validating
bad user input.  Info severity is more appropriate.

Change-Id: Ib8a4dd08570923c6cade6447b52bb73d20558258
Closes-Bug: #1272565
Merge "Reduce severity of log messages in validation methods"