gesture: messages and sensitivity changes for small (warmth) scales; devicelistener dedup (#6468)

* deduplicate code on warmth/brightness swipes

if device has a small scale (e.g. warmth is going from 0..10)
* adjust warmth message
* use a smaller gesture sensitivity

frontend/device/android/powerd.lua

@@ -20,6 +20,8 @@ function AndroidPowerD:init()
     if self.device:hasNaturalLight() then
         self.warm_diff = android:getScreenMaxWarmth() - android:getScreenMinWarmth()
         self.fl_warmth = self:getWarmth()
+        self.fl_warmth_min = android:getScreenMinWarmth()
+        self.fl_warmth_max = android:getScreenMaxWarmth()
     end
 end