The default pageName has the value of AppName/AppVersion and can be overwritten via passing the &&pageName key through contextData.
To overwrite the pageName you must pass the &&pageName key in the contextData
iOS Sample code snippet
NSMutableDictionary *contextData = [NSMutableDictionary dictionary];
[contextData setObject:@"MyCustomPageName" forKey:@"&&pageName"];
[ADBMobile collectLifecycleDataWithAdditionalData:contextData];
Android Sample code snippet
HashMap contextData = new HashMap();
contextData.put("MyCustomPageName", "&&pageName");
Config.collectLifecycleData(this, contextData);