On your Computer, open the Folder %Appdata% in this Folder there is a Stardew Valley Folder, and in this Folder is a Folder called "saves". Go into this Folder. In this Folder there are Folders like "924903482_YourName" - these are your Savegames. Copy all or just one of this Folders on your Android Phone in the Folder StardewValley in your root Folder (gets created after you create your first savegame on android). You then can load your savegame from PC on Android. You can too copy the Savegame back to your Computer to play it again on your Computer. TL;DR: you just need to copy your savegame from your android folder to your pc folder
im actually trying this out now and hopefully this works, i will do andriod to pc and hopefully vice versa