This is not technical advice and please understand all of the risks before proceeding but: 
In the past I have used a program called SyncThing to sync folders across multiple Android devices and PCs, in theory you should be able to do the same thing with the /save folder and it should make it available. However, it is to my understanding that if you are playing on different devices with the same save file then all versions of Stardew need to be the same version or it may corrupt/fail to play correctly. You should be mostly safe to take an unmodded, lower version save file to an unmodded, higher version of Stardew. So example being, you could port a 1.5 save file to 1.6 on PC but you couldn't play a 1.6 save file on an android device that is only able to play version 1.5, if that makes sense.