Survival games are resource managements at their core, are they not? Unless that's done in the game world and not the UI, I don't see the issue with UI taking the spotlight. If you're that worried, get creative with it so it shows up less. Hide the hunger, thirst and rest indicators so they show up with a button press, but are indicated in game art via emoticons over the player's head. Try playing stomach growl sounds every so often with low hunger to remind the player that they are in fact, hungry.
I've been there, so stressed that I simply forget I'm hungry until my stomach growls or I pass out. You can do this with your other needs, rest and thirst. Put some sprite animations so the player rubs their eyes, blur the screen a tiny bit, just enough to be noticeable. I think you can do that on Android without wrecking the GPU, though I am not experienced with shaders. I don't have any ideas for thirst but I'm sure you can come up with something if you pursue this path.
I encourage you do, the game looks pretty simplistic so it's going to need one of two things to stand out: interesting mechanics or character. Ultimately, you're the designer and I'm not getting paid to figure this out for you, so I'll let you figure it out.
