Created new Task.h file to contain task classes.

Test: tested Reboot {target} + Flash {partition} on raven device
Bug: 194686221
Change-Id: I0d80230d682f80af12cca9705df0172651bf4461
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 8f7cced..e739404 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -74,6 +74,7 @@
 #include "fastboot_driver.h"
 #include "fs.h"
 #include "super_flash_helper.h"
+#include "task.h"
 #include "tcp.h"
 #include "transport.h"
 #include "udp.h"