fix(esp32): Better flash duration

Previously, the photo was taken before the flash reached maximum
brightness so instead of sharp, white image, it was a poorly lit, green
tinted one.

This fixes that, at a cost of very slightly increased power consumption.

Author: dcelasun

esp32/m5stack_timer_camera_x.ino

@@ -118,8 +118,8 @@ WiFiClient connectToWiFi() {
 }
 
 bool sendImage(WiFiClient wifi) {
-    unit_flash_set_brightness(1);
-    delay(100);
+    unit_flash_set_brightness(9);
+    delay(300);
     if (!TimerCAM.Camera.get()) {
         unit_flash_set_brightness(0);
         Serial.println("Could not get camera");