Add more demo code

koom-demo/src/main/java/com/kwai/koom/demo/KOOMApplication.java

@@ -5,6 +5,8 @@
 import android.app.Application;
 
 import com.kwai.koom.javaoom.KOOM;
+import com.kwai.koom.javaoom.common.KConfig;
+import com.kwai.koom.javaoom.common.KLog;
 
 /**
  * Copyright 2020 Kwai, Inc. All rights reserved.
@@ -47,4 +49,39 @@ public void listenReportGenerateStatus() {
     });
   }
 
+  //Example of how to set custom config.
+  public void customConfig() {
+    KConfig kConfig = new KConfig.KConfigBuilder()
+            .heapRatio(85.0f) //heap occupied ration in percent, 85.0f means use 85% memory of max heap
+            .rootDir(this.getCacheDir().getAbsolutePath()) //root dir stores report and hprof files
+            .heapOverTimes(3) //heap max times of over heap's used threshold
+            .build();
+    KOOM.getInstance().setKConfig(kConfig);
+  }
+
+  //Example of how to set custom logger.
+  public void customLogger() {
+    KOOM.getInstance().setLogger(new KLog.KLogger() {
+      @Override
+      public void i(String TAG, String msg) {
+        //get the log of info level
+      }
+
+      @Override
+      public void d(String TAG, String msg) {
+        //get the log of debug level
+      }
+
+      @Override
+      public void e(String TAG, String msg) {
+        //get the log of error level
+      }
+    });
+  }
+
+  //Example of set custom koom root dir.
+  public void customRootDir() {
+    KOOM.getInstance().setRootDir(this.getCacheDir().getAbsolutePath());
+  }
+
 }