Sound quality from a phone is most certainly going to suck, conversations are going to be barely intelligible when in your pocket, and battery life will be disappointing compared to a dedicated recorder. There certainly are phone applications that allow constant background audio recording, but none of them are perfect from what I'm aware of (Android really doesn't want you to run applications consistently without inconveniences, even disabling all optimizations). I think using a program like Echo [0], that constantly records in the background rolling over a certain user-defined amount of time/device memory and lets you save the past X minutes available when needed and user-controlled is more convenient (and I don't really see a lot of good 24/7 applications around from a brief look). In any case, you could sync the recordings of the application of your choice with synching instead of using a cloud solution. Best would be to find one that supports opus encoding for maximum size efficiency.
If your plan is generous enough, call your home recorder.
Automate moving the recordings from your phone? IFTT (If This, Then That) used to be a thing but I never played with it.
"constant recording": are you really sure you need that? Do you plan to go back through it and filter the majority of non interesting time out, somehow? Or do you really want the sound of every keyboard clack and digestive announcement saved for posterity?
My first thought was "what will you use for a mic?" but I'm guessing you're happy with what your phone gives from the rest of the post. If you wanted an actual "sound sensor" record of an area then the choice of mic becomes more important and if you're wearing it i think yer boned and will get more clothing noise than useful signal.