Remove unnecessary header file includes for drmserver

#define LOG_TAG "drmserver"

//#define LOG_NDEBUG 0

#include <sys/types.h>

#include <unistd.h>

#include <grp.h>

#include <binder/IPCThreadState.h>

#include <binder/ProcessState.h>

#include <binder/IServiceManager.h>

#include <utils/Log.h>

#include <private/android_filesystem_config.h>

#include <DrmManagerService.h>