可以尝试在工程的CMakeLists.txt文件中手动添加OpenSSL库的include路径，以解决找不到include文件的问题。具体步骤如下：

1. 在build.gradle文件中添加OpenSSL库的依赖：

dependencies {
    implementation 'org.conscrypt:conscrypt-android:2.5.1'
}

2. 在CMakeLists.txt文件中添加以下代码进行OpenSSL库的引用和include路径的设置：

find_library( # Defines the name of the path variable that stores the
              # location of the NDK library.
              ssl-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              ssl)

find_library( # Defines the name of the path variable that stores the
              # location of the NDK library.
              crypto-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              crypto)

# 引用OpenSSL库
target_link_libraries(your-project ssl-lib crypto-lib)

# 设置include路径
target_include_directories(your-project PRIVATE path-to-openssl-include-dir)

其中，path-to-openssl-include-dir为OpenSSL库中include文件所在的路径。

通过以上步骤，即可成功引用OpenSSL库并设置include路径，解决编译时找不到include文件的问题。