Move librecovery_ui to a sub-directory

This helps to expose librecovery_ui for device specific RecoveryUi.

Bug: 76436783
Test: mma, unit tests pass
Change-Id: Ic6c3d301d5833e4a592e6ea9d9d059bc4e4919be
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index 53a2adc..1aa7de6 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -19,6 +19,6 @@
 #include <string>
 #include <vector>
 
-#include "device.h"
+#include "recovery_ui/device.h"
 
 Device::BuiltinAction StartFastboot(Device* device, const std::vector<std::string>& args);