android: Don't rely on indirect inclusion of unistd.h

The standard C library close() and lseek() functions require inclusion
of the unistd.h header. Include it explicitly where needed instead of
relying on indirect inclusion.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Tested-by: Paul Elder <paul.elder@ideasonboard.com>

src/android/camera_worker.cpp

@@ -10,6 +10,7 @@
 #include <errno.h>
 #include <string.h>
 #include <sys/poll.h>
+#include <unistd.h>
 
 #include "camera_device.h"