Add getExportedNamespace NB callback

This callback replaces getVendorNamespace(). Fix nativeloader
to use NativeBridgeGetExportedNamespace instead of
NativeBridgeGetVendorNamespace.

Bug: http://b/121248172
Bug: http://b/121372395
Test: make
Change-Id: I8fa2081e37815f6f65490c9536bed0687b7f1e77
diff --git a/libnativebridge/libnativebridge.map.txt b/libnativebridge/libnativebridge.map.txt
index a616b85..a6841a3 100644
--- a/libnativebridge/libnativebridge.map.txt
+++ b/libnativebridge/libnativebridge.map.txt
@@ -24,7 +24,7 @@
     NativeBridgeGetError;
     NativeBridgeIsPathSupported;
     NativeBridgeCreateNamespace;
-    NativeBridgeGetVendorNamespace;
+    NativeBridgeGetExportedNamespace;
     NativeBridgeLinkNamespaces;
     NativeBridgeLoadLibraryExt;
     NativeBridgeInitAnonymousNamespace;