Fix several crash errors triggered by legacy code (#2962)

frontend/device/android/powerd.lua

@@ -9,8 +9,8 @@ local AndroidPowerD = BasePowerD:new{
 function AndroidPowerD:init()
 end
 
-function AndroidPowerD:setIntensityHW()
-    android.setScreenBrightness(math.floor(255 * self.fl_intensity / 25))
+function AndroidPowerD:setIntensityHW(intensity)
+    android.setScreenBrightness(math.floor(255 * intensity / 25))
 end
 
 function AndroidPowerD:getCapacityHW()

frontend/device/kindle/powerd.lua

@@ -29,7 +29,7 @@ function KindlePowerD:setIntensityHW(intensity)
     if self.lipc_handle ~= nil and intensity > 0 then
         -- NOTE: We want to bypass setIntensity's shenanigans and simply restore the light as-is
         self.lipc_handle:set_int_property(
-            "com.lab126.powerd", "flIntensity", self.fronglightIntensity())
+            "com.lab126.powerd", "flIntensity", intensity)
     else
         -- NOTE: when intensity is 0, We want to really kill the light, so do it manually
         -- (asking lipc to set it to 0 would in fact set it to 1)...
@@ -73,7 +73,7 @@ function KindlePowerD:afterResume()
     if self:isFrontlightOn() then
         -- Kindle stock software should turn on the front light automatically. The follow statement
         -- ensure the consistency of intensity.
-        self:setIntensityHW()
+        self:turnOnFrontlightHW()
     else
         self:turnOffFrontlightHW()
     end

frontend/device/kobo/powerd.lua

@@ -45,7 +45,7 @@ end
 
 function KoboPowerD:setIntensityHW(intensity)
     if self.fl == nil then return end
-    self.fl:setBrightness(self.frontlightIntensity())
+    self.fl:setBrightness(intensity)
     self:_syncNickelConf()
 end