I have ACER Liquid X2 S59 (Triple-SIM, 3xSIM), which is still in 2021 the most powerful Triple SIM smartphone in the market. It was widely distributed only in SE Asia but it has obsolete Android 5 Lollipop. Acer Liquid X2 - Full phone specifications
So I want to build OS based on newer Android. And there is big community of users in Philippines that would appreciate some update.
I’m engineer with various programming skills but never worked with mobile OS.
Is there any starting-kit for developer newbies?
I need to decide what version of /e/OS and core version of Android to choose.