Make dlext_namespaces.h available to users of libnativeloader

Bug: 33531483
Test: build
Change-Id: I1da92e2b1437b6775a9d81fc6c1a2d4bacecbc04
(cherry picked from commit 0936d25371e4f2618bf5760583a60dd542740542)
diff --git a/libnativeloader/dlext_namespaces.h b/libnativeloader/include/nativeloader/dlext_namespaces.h
similarity index 100%
rename from libnativeloader/dlext_namespaces.h
rename to libnativeloader/include/nativeloader/dlext_namespaces.h
diff --git a/libnativeloader/native_loader.cpp b/libnativeloader/native_loader.cpp
index 94c46fc..d7b5cb5 100644
--- a/libnativeloader/native_loader.cpp
+++ b/libnativeloader/native_loader.cpp
@@ -20,7 +20,7 @@
 #include <dlfcn.h>
 #ifdef __ANDROID__
 #define LOG_TAG "libnativeloader"
-#include "dlext_namespaces.h"
+#include "nativeloader/dlext_namespaces.h"
 #include "cutils/properties.h"
 #include "log/log.h"
 #endif