Fix a compile warning due to missing include (#2293)

Compilation in strict mode fails with
```
wasm_micro_runtime/core/shared/platform/android/platform_init.c:122:30:
  error: declaration of 'struct epoll_event` will not be visible outside of this
  function [-Werror,-Wvisibility]

  epoll_pwait(int epfd, struct epoll_event *events, int maxevents, int timeout,
                               ^
1 error generated.
```

Co-authored-by: Misha Gridnev <gridman@google.com>

core/shared/platform/android/platform_internal.h

@@ -27,6 +27,7 @@
 #include <sched.h>
 #include <errno.h>
 #include <netinet/in.h>
+#include <sys/epoll.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/mman.h>