BackendUnifiedServiceManager: tidy up includes

This was breaking Linux Binder IPC (WIP) build.

Bug: 341997808
Test: mma
Change-Id: Ic3f25c9c49773d4f7c759e8318513f166ec2d995
diff --git a/libs/binder/BackendUnifiedServiceManager.cpp b/libs/binder/BackendUnifiedServiceManager.cpp
index 496c5ef..b0d3048 100644
--- a/libs/binder/BackendUnifiedServiceManager.cpp
+++ b/libs/binder/BackendUnifiedServiceManager.cpp
@@ -15,6 +15,10 @@
  */
 #include "BackendUnifiedServiceManager.h"
 
+#if defined(__BIONIC__) && !defined(__ANDROID_VNDK__)
+#include <android-base/properties.h>
+#endif
+
 namespace android {
 
 using AidlServiceManager = android::os::IServiceManager;