当我使用透明Activity时，退出透明Activity时Apng会卡主线程，造成OnDestory延迟调用

[fuxuanyang11]

New Issue Checklist

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Issue Info

如图

Info	Value
Device Info	任何手机
System Version	e.g. 6.0
APNG4Android Library Version	2.24.0
Repro rate	e.g. all the time (100%) / sometimes x% / only once
Repro with our demo project	e.g. does it happen with our demo project?
Demo project link	e.g. link to a demo project that highlights the issue

Issue Description and Steps

Please fill in the detailed description of the issue (full output of any stack trace, compiler error, ...) and the steps to reproduce the issue.

[jingpeng]

Android App开发中onDestroy本就不会立刻调用，系统自行决定onDestroy调用时机