What is required to have a language added in Android as a language system?

My language is Chichewa or Chinyanja and is spoken by millions of people across 3 countries. More people are using android gadgets but it does not support Chichewa. We can see that other languages like Kiswahili which use the same rules like ours is supported. What is are the qualifications for a language to be added to android as a system language. Thanks in advance for your help