There is a test which shows how it supposed to work.
This parser ignores everything until it meet the desired string then read it and stopped reading the stream:

"some rubbish at the beginning..."
				+ GlobalUsageSettings.REMOTEPROPS_USAGE_REPORTING_ENABLED_KEY
+ enablementValue
+ "\n"
+ "#"
+ "some rubbish at the end".

I have no idea why it was important. It's not what we want for a new usage.properties file anyway.