Include sys/types.h for uid_t
```
system/core/libmodprobe/include/exthandler/exthandler.h:22:37: error: unknown type name 'uid_t'; did you mean 'pid_t'?
```
Bug: 190084016
Change-Id: Iff7cb5e34474f00f200edbaf4895713576b0a6fc
diff --git a/libmodprobe/include/exthandler/exthandler.h b/libmodprobe/include/exthandler/exthandler.h
index 232aa95..a619f81 100644
--- a/libmodprobe/include/exthandler/exthandler.h
+++ b/libmodprobe/include/exthandler/exthandler.h
@@ -17,6 +17,7 @@
#pragma once
#include <android-base/result.h>
#include <string>
+#include <sys/types.h>
android::base::Result<std::string> RunExternalHandler(
const std::string& handler, uid_t uid, gid_t gid,