Unity Android构建报错：版本切换后gradle依赖问题无法解决

我在使用Unity 2021.3.7f1开发Android游戏时遇到构建问题：之前为解决APK权限问题，临时将Unity版本切换到2022.3.29f1，切回原版本后就无法完成构建，一直报找不到gradle依赖的错误。

我已经尝试过以下操作，但都没有解决问题：

• 删除gradle.properties文件中的r8相关条目
• 手动修改build.gradle文件，把gradle引用版本从7.1.2改成6.1.1

报错详情如下：

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':launcher'.
> Could not resolve all artifacts for configuration ':launcher:classpath'.
   > Could not find com.android.tools.build:gradle:6.1.1.
     Searched in the following locations:
       - https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/6.1.1/gradle-6.1.1.pom
       - https://jcenter.bintray.com/com/android/tools/build/gradle/6.1.1/gradle-6.1.1.pom
     Required by:
         project :launcher

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8

UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

我可以补充更多项目或环境细节，恳请大家帮忙解决。

内容的提问来源于stack exchange，提问作者Matt Radin