dryRun not honored when using values of 1 and 0 about gcm HOT 5 CLOSED

Inside here obviously:
public class Sender {
...
public Result sendNoRetry(...)
...
}

Per the docs:

dry_run -  If included, allows developers to test their request without 
actually sending a message. Optional. The default value is false, and must be a 
JSON boolean.
http://developer.android.com/google/gcm/gcm.html

Have you tried using 

if (dryRun != null) {
      addParameter(body, PARAM_DRY_RUN, dryRun ? "1" : "0");
    }

+1 This is happening to me as well, and per the Android Developer docs 
PARAM_DRY_RUN (aka "dry_run") needs to be a JSON boolean. Thus will only 
support values of "true" or "false" and not the "1" or "0" that is in the code.