android: fix frontlight dialog gesture (#6568)

frontend/device/devicelistener.lua

@@ -227,8 +227,7 @@ if Device:hasFrontlight() then
     end
 
     function DeviceListener:onShowFlDialog()
-        local FrontLightWidget = require("ui/widget/frontlightwidget")
+        Device:showLightDialog()
-        UIManager:show(FrontLightWidget:new{})
     end
 
 end

frontend/device/generic/device.lua

@@ -296,6 +296,12 @@ function Device:onPowerEvent(ev)
     end
 end
 
+function Device:showLightDialog()
+    local FrontLightWidget = require("ui/widget/frontlightwidget")
+    local UIManager = require("ui/uimanager")
+    UIManager:show(FrontLightWidget:new{})
+end
+
 function Device:info()
     return self.model
 end