Don't log potentially personally identifiable information at Error/Warning/Info levels

I've demoted possible PII to debug logging level. This includes things like
full response strings, key/value pairs of mapping data, etc, since this could
contain sensitive data. My assumption in doing this is that apps should be
able to ship with their logging levels set to Info, and not risk sending any
sensitive data to any 3rd parties that collect app logging, such as Crashlytics.