Fix SSID, Password String release crash (#28853)

diff --git a/src/controller/java/AndroidDeviceControllerWrapper.cpp b/src/controller/java/AndroidDeviceControllerWrapper.cpp
index 2b8c699..f81d8c1 100644
--- a/src/controller/java/AndroidDeviceControllerWrapper.cpp
+++ b/src/controller/java/AndroidDeviceControllerWrapper.cpp
@@ -535,11 +535,13 @@
     {
         env->ReleaseStringUTFChars(ssidStr, ssid);
         env->DeleteGlobalRef(ssidStr);
+        ssidStr = nullptr;
     }
     if (passwordStr != nullptr)
     {
         env->ReleaseStringUTFChars(passwordStr, password);
         env->DeleteGlobalRef(passwordStr);
+        passwordStr = nullptr;
     }
     if (operationalDatasetBytes != nullptr)
     {