Bluetooth: Replace assert() with CHECK()

#include "vendor_interface.h"

#include <assert.h>

#define LOG_TAG "android.hardware.bluetooth@1.0-impl"

#include <android-base/logging.h>

#include <cutils/properties.h>

    InitializeCompleteCallback initialize_complete_cb,

    PacketReadCallback event_cb, PacketReadCallback acl_cb,

    PacketReadCallback sco_cb) {

  assert(!g_vendor_interface);

  CHECK(!g_vendor_interface);

  g_vendor_interface = new VendorInterface();

  return g_vendor_interface->Open(initialize_complete_cb, event_cb, acl_cb,

                                  sco_cb);