java.lang.NullPointerException: Attempt to invoke virtual method 'int com.idlefish.flutterboost.Platform.whenEngineStart()' on a null object reference

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tencent.wemeet.app/com.idlefish.flutterboost.containers.BoostFlutterActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'int com.idlefish.flutterboost.Platform.whenEngineStart()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3897)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4076)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2473)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:219)
at android.app.ActivityThread.main(ActivityThread.java:8349)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1055)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int com.idlefish.flutterboost.Platform.whenEngineStart()' on a null object reference
at com.idlefish.flutterboost.containers.FlutterActivityAndFragmentDelegate.onAttach(FlutterActivityAndFragmentDelegate.java:89)
at com.idlefish.flutterboost.containers.BoostFlutterActivity.onCreate(BoostFlutterActivity.java:145)
at android.app.Activity.performCreate(Activity.java:8085)
at android.app.Activity.performCreate(Activity.java:8073)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1320)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3870)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4076) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2473) 
at android.os.Handler.dispatchMessage(Handler.java:110) 
at android.os.Looper.loop(Looper.java:219) 
at android.app.ActivityThread.main(ActivityThread.java:8349) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1055)

## Steps to Reproduce
**A small application to reproduce the bug(最小化可复现的demo)**

1. ...
2. ...
3. ...

**Flutter Boost Version** 1.17.1
**Target Platform:**. mac
**Target OS version/browser:** android
**Devices:** 荣耀

## Logs
add your crash log or something else.

```
```

Start with FlutterActivityAndFragmentDelegate.java:89 and BoostFlutterActivity.java:145, where the reported Android launch fails, then reproduce the crash with Flutter Boost 1.17.1. Trace why Platform is null during onAttach and verify that launching the activity no longer produces the reported NullPointerException.

Written by the indexing model from the issue text.