Unset fields in MeterStatsResponseConvertor

I discovered two bugs while creating unit tests for MultipartReplyTranslator (MeterConfig case - please see MultipartReplyTranslatorFifthTest#testMeterConfigStats()).

#1:
In MeterStatsResponseConvertor#toSALMeterConfigList() the meterConfigStatsBuilder.setFlags() is not set. So the flags return null instead of boolean value.

#2:
In MeterStatsResponseConvertor#toSALMeterConfigList(), in case of a band of type MeterBandDscpRemarkCase is received, dscpRemarkBuilder.setPercLevel() is not set either (+ just typo - should be PrecLevel())