Uh... This shouldn't happen in normal circumstances and I 100% have my previous saves with each mobile update. Ensure that you are installing the new apk as an update. + it can be worth checking your security software because I'm not a certified developer for Android and some sec packages are allergic to this.
Still, it's weird that you have 0.2 saves only. Can you make a new save in a different slot at all inside a version? If you can, then this means they aren't deleted, but stored in a different folder for reason. Maybe different profiles for different users? Also, it may be worth a shot making a manual download and not using the auto-update from Jenkins or whatever that Itch client is called.