Two fixes for light transitioning issues

* When turning off the light at a low brightness setting,
  the LEDs were seen flashing brightly for a short time.

* Transitioning did not work when turning of the light. The light would be
  kept at normal brightness during the transition and then it turned of
  at once. This looks like an issue in the ESPHome transitioning code,
  because that is the code that is responsible for the transitioning.
  When turning on the light, it works correctly. I see both the state
  and the brightness go up. But when turning off the light, I see that
  the state decreases  gradually to zero, but the brightness is kept
  as-is. I wrote a fix for this behavior in my code and will investigate
  if the ESPHome code can be fixed for this.

yeelight_bs2.h

@@ -80,40 +80,44 @@ class YeelightBedsideLampV2LightOutput : public Component, public LightOutput
 
   void turn_off_()
   {
-    master2_->turn_off();
-    master1_->turn_off();
-    red_->turn_off();
-    green_->turn_off();
-    blue_->turn_off();
-    white_->turn_off();
+      master2_->turn_off();
+      master1_->turn_off();
+      red_->turn_off();
+      green_->turn_off();
+      blue_->turn_off();
+      white_->turn_off();
   }
 
   void turn_on_in_rgb_mode_(float red, float green, float blue, float brightness)
   {
-    ESP_LOGD("custom", "Activate RGB %f, %f, %f, BRIGHTNESS %f", red, green, blue, brightness);
-
-    // Compensate for brightness.
-    red = red * brightness;
-    green = green * brightness;
-    blue = blue * brightness;
-
-    // Inverse the signal. The LEDs in the lamp's circuit are brighter
-    // when the voltages on the GPIO pins are lower.
-    red = 1.0f - red;
-    green = 1.0f - green;
-    blue = 1.0f - blue;
-
-    float white = 0.0;
-
-    ESP_LOGD("rgb_mode", "LED state : RGBW %f, %f, %f, %f", red, green, blue, white);
-
-    // Drive the LEDs.
-    red_->set_level(red);
-    green_->set_level(green);
-    blue_->set_level(blue);
-    white_->set_level(white);
-    master1_->turn_on();
-    master2_->turn_on();
+      ESP_LOGD("custom", "Activate RGB %f, %f, %f, BRIGHTNESS %f", red, green, blue, brightness);
+
+      // The brightness must be at least 3/100 to light up the LEDs.
+      if (brightness < 0.03)
+          brightness = 0.03;
+
+      // Compensate for brightness.
+      red = red * brightness;
+      green = green * brightness;
+      blue = blue * brightness;
+
+      // Inverse the signal. The LEDs in the lamp's circuit are brighter
+      // when the voltages on the GPIO pins are lower.
+      red = 1.0f - red;
+      green = 1.0f - green;
+      blue = 1.0f - blue;
+
+      float white = 0.0;
+
+      ESP_LOGD("rgb_mode", "LED state : RGBW %f, %f, %f, %f", red, green, blue, white);
+
+      // Drive the LEDs.
+      red_->set_level(red);
+      green_->set_level(green);
+      blue_->set_level(blue);
+      white_->set_level(white);
+      master1_->turn_on();
+      master2_->turn_on();
   }
 
   void turn_on_in_color_temperature_mode_(float temperature, float brightness)