Using dlib-19.4.0 in android for realtime face recognition

I followed this github project for dlib download on android. I was able to run this thing on my android device. For face recognition and sign recognition, it worked fine. But I want to have a face recognition feature in my application that I am reading, possibly in dlib-19.4.0. I even tried it in python and it worked.

I want to import this function into my android app. I followed the instructions to build the .so files. But in the .so files, I couldn't find the face_recognition functions. Could you please help me with this. Here is my CMAKE file:

#-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
cmake_minimum_required(VERSION 3.4.1)

message("Checking CMAKE_SYSTEM_NAME = '${CMAKE_SYSTEM_NAME}'")
if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
  add_definitions(-DOS_OSX)
elseif (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
  add_definitions(-DOS_LINUX)
elseif (${CMAKE_SYSTEM_NAME} MATCHES "Windows")
  add_definitions(-DOS_WIN)
elseif (${CMAKE_SYSTEM_NAME} MATCHES "Android")
  add_definitions(-DOS_ANDROID)
  message("Checking CMAKE_ABI_NAME = '${CMAKE_ANDROID_ARCH_ABI}'")
else()
  message("OS not detected.")
endif()

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wall -Werror")

## Define each subfolders
set(JNI_DETECTION_INCLUDE jni/jni_detections)
set(JNI_DETECTION_SRC jni/jni_detections)
set(JNI_COMMON_INCLUDE jni)
set(JNI_COMMON_SRC jni/jni_common)
set(DLIB_DIR dlib)
set(EXT_DIR third_party)
set(GLOG_INCLUDE_DIR ${EXT_DIR}/miniglog)
set(OPENCV_PREBUILT ${EXT_DIR}/OpenCV-android-sdk/sdk/native/jni)

# Opencv and it will use static import
set(ANDROID_NDK_ABI_NAME ${CMAKE_ANDROID_ARCH_ABI})
include(${OPENCV_PREBUILT}/OpenCVConfig.cmake)

# Include headers
include_directories(${DLIB_DIR} ${OpenCV_INCLUDE_DIRS} ${GLOG_INCLUDE_DIR} ${JNI_COMMON_INCLUDE} ${JNI_DETECTION_INCLUDE} include)

# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds it for you.
# Gradle automatically packages shared libraries with your APK.

add_library( # Sets the name of the library.
             native-lib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             # Associated headers in the same location as their source
             # file are automatically included.
             ${DLIB_DIR}/dlib/cpp/cpp/native-lib.cpp
 )


add_library(dlib.cpp
             SHARED
            ${DLIB_DIR}/dlib/cpp/cpp/dlib.cpp
 )

add_library(matrix.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/matrix.cpp
 )

add_library(vector.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/vector.cpp
 )

add_library(svm_c_trainer.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/svm_c_trainer.cpp
 )

add_library(svm_rank_trainer.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/svm_rank_trainer.cpp
 )

add_library(decision_functions.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/decision_functions.cpp
 )

add_library(other.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/other.cpp
 )

add_library(basic.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/basic.cpp
 )

add_library(cca.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/cca.cpp
 )

add_library(sequence_segmenter.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/sequence_segmenter.cpp
 )

add_library(svm_struct.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/svm_struct.cpp
 )

add_library(image.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/image.cpp
 )

add_library(rectangles.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/rectangles.cpp
 )

add_library(object_detection.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/object_detection.cpp
 )

add_library(shape_predictor.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/shape_predictor.cpp
 )

add_library(correlation_tracker.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/correlation_tracker.cpp
 )

add_library(face_recognition.cpp
             SHARED
             ${DLIB_DIR}/dlib/cpp/cpp/face_recognition.cpp
 )


# Searches for a specified prebuilt library and stores the path as a
# variable. Because system libraries are included in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
              log-lib

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

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in the
# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )