To ensure "genetic" variation
Let's look at why there are two sexes in humans and many (most?) other animals. Why did we go from cells that copy themselves, to large organisms that actually need to mate with other large organism to reproduce?
Well, one reason might be to diversify the gene pool. If one creature keeps cloning himself, and those clones keep cloning themselves, you ultimately end up with an entire species that are all pretty much the same. Which is fine as long as the environment doesn't change, but if suddenly the environment changes to one that is bad for one of the species, it could be the downfall of the entire species. The only hope for such a species is a few errors during copying, so that the small amount of mutant might thrive while the rest dies.
That's why two-gender reproduction is quite useful. When two people have children, they can be anywhere between 100% parent1 and 100% parent2, and with tons of errors as well, because of the inherent difficulty of combining genes from two parents. This leads to a species that is basically full of mutants, so much so that you can have them in many different colors, lengths, strengths and weaknesses. Many of them will be inferior given normal condition, but the species is extremely well suited to handle large environmental changes.
So maybe your android society 1.0 actually didn't have any genders, but due to some environmental change they all become obsolete or inferior. After which they started to introduce "intentional bugs", random errors that would create "mutants" within the society. But the problem with these mutants was that they simply could not compete with their perfect counterparts during "normal" circumstances, so they were never reproduced. Finally, they decided to split the society into two genders: mutants and clones. Mutants are created by taking the average of both parents genes*, and then adding random errors to them. Clones are creating by simply taking anywhere between 25% and 75% of the genes* of either parents, without errors. And only mutants and clones can reproduce together, to make sure that you do not end up with a society full of clones, but still a society that values clones of succesful androids.
It's a flimsy story full of holes, but frankly if you insist on putting sexes/genders into your android-story (which feels a bit like putting teenage girls into your werewolf story) this might be your best solution.
Also note that I am by no means a biologist, and you should definately fact check me about why there are even different sexes to begin with.
*genes being the "source code" or "design specification".