fix crash on find method ClashException

core/src/main/java/com/github/kr328/clash/core/bridge/ClashException.java

@@ -1,6 +1,9 @@
 package com.github.kr328.clash.core.bridge;
 
+import androidx.annotation.Keep;
+
 public class ClashException extends Exception {
+    @Keep
     public ClashException(String msg) {
         super(msg);
     }