Hi there!
I hope this will help
//trying to click the dropdown list
try{
WebElement parentElement1 = driver.findElement(By.id("retProdOp0"));
WebElement childElement1 = parentElement1.findElement(By
.xpath("//android.view.View[@index='1']"));
childElement1.click();
driver.label("dropdown list 2nd element clicked");
}catch(Exception e){
driver.label("Failed to click dropdown list on prodexchg screen");
System.out.println(e.getMessage());
}