fix: Android max brightness issue

Author: lihuanke

android/src/main/java/org/capslock/RNDeviceBrightness/RNDeviceBrightnessModule.java

@@ -3,8 +3,10 @@
  */
 
  package org.capslock.RNDeviceBrightness;
-
  import android.app.Activity;
+ import android.content.Context;
+ import android.os.PowerManager;
+ import android.util.Log;
  import android.view.WindowManager;
  import android.provider.Settings;
 
@@ -15,6 +17,9 @@
  import com.facebook.react.bridge.ReactMethod;
  import com.facebook.react.bridge.Promise;
  import android.content.res.Resources;
+
+ import java.lang.reflect.Field;
+
  public class RNDeviceBrightnessModule extends ReactContextBaseJavaModule {
    private static final int BRIGHTNESS_MAX = 255;
    private static final int BRIGHTNESS_MIN = 0;
@@ -57,6 +62,10 @@ public void getBrightnessLevel(Promise promise) {
     */
    private int getBrightnessMax() {
        try {
+         int maxBri = getMaxBrightness(getReactApplicationContext(), BRIGHTNESS_MAX);
+         if (maxBri != 0) {
+             return maxBri;
+         }
          Resources system = Resources.getSystem();
          int resId = system.getIdentifier("config_screenBrightnessSettingMaximum", "integer", "android");  // API17+
          if (resId != 0) {
@@ -67,6 +76,31 @@ private int getBrightnessMax() {
        }
        return BRIGHTNESS_MAX;
    }
+
+    /**
+     * 获取最大亮度（通过PowerManager的方式）
+     * @param context
+     * @param defaultValue
+     * @return [int]max brightness
+     */
+    private int getMaxBrightness(Context context, int defaultValue){
+       PowerManager powerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
+       if(powerManager != null) {
+           Field[] fields = powerManager.getClass().getDeclaredFields();
+           for (Field field: fields) {
+               // https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/java/android/os/PowerManager.java
+               if(field.getName().equals("BRIGHTNESS_ON")) {
+                   field.setAccessible(true);
+                   try {
+                       return (int) field.get(powerManager);
+                   } catch (IllegalAccessException e) {
+                       return defaultValue;
+                   }
+               }
+           }
+       }
+       return defaultValue;
+   }
 
    @ReactMethod
    public void getSystemBrightnessLevel(Promise promise){