If you are going to be presenting your self as knowledgeable on the subject, then you need to refrain from saying 'long time' it's vague.
Under regular conditions, its in the range of minutes, maybe up to hours.
RNA isn't that stable. (In labs, it needs to be handled specially. You need to either freeze it a deep temperatures (you put your RNA samples in the -80C freezer) or copy/convert it to DNA (use a reverse-transcriptase to make much more stable DNA out of it).
The number one way ti's transmitted bird to bird is through shared drinking water.
...as in one birds poops into the water while another is drinking (= oro-fecal pathway I mentioned 2 levels higher in the thread). Not as in 2 birds which happen to drink from the same river a few apart. You need a time frame of a few minutes up to a couple of hours max.
(In birds, poop contains the biggest amount of virus, and as it moist and protects from light, viruses have the highest chance for surviving a longer time).
It's the bird's equivalent of humans sneezing on each other's face. (You can catch flu this way. Whereas, your risks of catching flu by walking in the same room as where someone sneeze the day before are bleak) (in humans that's aerosol/particulate transmission).
But handling raw chicken with the virus can cause it to spread.
By the time the chicken reaches the kitchen, most of the virus will probably have died/become inactive. Chance of transmission at this point in the chain of the poultry production are low. But are much higher at the other side of the chain.
At some point of time the dead chicken in your dish (and in the kitchen of the restaurant where you're eating) used to be alive (I realise that I'm starting to sound like a Monthy Python's sketch).
This chicken has been slaughtered, de feathered, butchered and otherwise conditioned before being sent to the restaurant.
At that point of time, the chicken was alive not so long ago (so there should be still active virus in it), and the whole preparation is bound to release quite a lot of the virus in the air. People working at this point in the chain (very often the farmers themselves) are at a higher risk.
We're still speaking of only a dozen of people per year, though.
Now the problem is that this transmission (bird-to-human) is so rare, that we don't really have enough stats to support this kind of conclusion. All I can say is that all the bird-to-human transmission I've heard about in the past were in people handling the birds (farmers, and the like), none of them were people working in the kitchen of restaurants service poultry, nor people eating chicken.
But well, with such a small pool (a dozen of cases per year) nothing is really 100% sure. We definitely lack enough data to give the exact life-time of a virus, or the odds of infection at each precise stage of poultry preparation, between the farm all the way to your dish.
And any way, this is bio science, not hardcore-hard science. Anything can happen anyway (although we're slowly drifting into the kind of "anything" territory, as western people in big city catching malaria although they've never travelled abroad ever, but just happen to live near an airport, and managed to get bitten by a mosquito which travelled all the way from Africa while trapped on a plain. This kind of Rube Goldbergesque situation does happen, but we're speaking single-digit amount of cases in total)