unit_test: Make global legacy mocks thread safe

#include <bluetooth/log.h>

#include <map>

#include <mutex>

#include "os/log.h"

std::mutex mutex_{};

static std::map<std::string, int>& _get_func_call_count_map() {

  static std::map<std::string, int> mock_function_count_map;

}

int get_func_call_count(const char* fn) {

  std::lock_guard<std::mutex> lock(mutex_);

  return _get_func_call_count_map()[fn];

}

void inc_func_call_count(const char* fn) { _get_func_call_count_map()[fn]++; }

void inc_func_call_count(const char* fn) {

  std::lock_guard<std::mutex> lock(mutex_);

  _get_func_call_count_map()[fn]++;

}

void reset_mock_function_count_map() { _get_func_call_count_map().clear(); }

void reset_mock_function_count_map() {

  std::lock_guard<std::mutex> lock(mutex_);

  _get_func_call_count_map().clear();

}

int get_func_call_size() { return _get_func_call_count_map().size(); }

int get_func_call_size() {

  std::lock_guard<std::mutex> lock(mutex_);

  return _get_func_call_count_map().size();

}

void dump_mock_function_count_map() {

  std::lock_guard<std::mutex> lock(mutex_);

  bluetooth::log::info("Mock function count map size:{}",

                       _get_func_call_count_map().size());