Add Brightness Util to check for platform before increasing brightness (#1096)

lib/utils/brightness_util.dart

@@ -0,0 +1,23 @@
+import 'package:cake_wallet/utils/device_info.dart';
+import 'package:device_display_brightness/device_display_brightness.dart';
+
+class BrightnessUtil {
+  static Future<void> changeBrightnessForFunction(Future<void> Function() func) async {
+    // if not mobile, just navigate
+    if (!DeviceInfo.instance.isMobile) {
+      func();
+      return;
+    }
+
+    // Get the current brightness:
+    final brightness = await DeviceDisplayBrightness.getBrightness();
+
+    // ignore: unawaited_futures
+    DeviceDisplayBrightness.setBrightness(1.0);
+
+    await func();
+
+    // ignore: unawaited_futures
+    DeviceDisplayBrightness.setBrightness(brightness);
+  }
+}