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/recovery_main.cpp b/recovery_main.cpp
index 935d698..2f5a184 100644
--- a/recovery_main.cpp
+++ b/recovery_main.cpp
@@ -49,16 +49,16 @@
 #include <selinux/selinux.h>
 
 #include "common.h"
-#include "device.h"
 #include "fastboot/fastboot.h"
 #include "logging.h"
 #include "minadbd/minadbd.h"
 #include "otautil/paths.h"
 #include "otautil/sysutil.h"
 #include "recovery.h"
+#include "recovery_ui/device.h"
+#include "recovery_ui/stub_ui.h"
+#include "recovery_ui/ui.h"
 #include "roots.h"
-#include "stub_ui.h"
-#include "ui.h"
 
 static constexpr const char* COMMAND_FILE = "/cache/recovery/command";
 static constexpr const char* LOCALE_FILE = "/cache/recovery/last_locale";