Fix CtsJniTestCases

The linker_namespaces test need android_get_LD_LIBRARY_PATH function.

Bug: http://b/129479780
Test: atest CtsJniTestCases
Change-Id: Iba5f74e1e4b5b1de173150120293102524db2507
(cherry picked from commit 91b0c68009c6d6efbaab8f268a5c9afb141c5ab4)
diff --git a/libdl/libdl.map.txt b/libdl/libdl.map.txt
index b4b4117..473bdf2 100644
--- a/libdl/libdl.map.txt
+++ b/libdl/libdl.map.txt
@@ -43,5 +43,6 @@
 
 LIBC_PLATFORM {
   global:
+    android_get_LD_LIBRARY_PATH;
     __cfi_init;
 } LIBC_OMR1;