linker: Add support for "whitelisted" property in linker config files

In order to enable no-vendor-variant VNDK, we need a way to restrict a
namespace to only a list of whitelisted libraries.  We add a new
"whitelisted" property for this.  If the property is not set, all
libraries in the search paths are available in a namespace.  If the
property is set, only the libraries named are available.

Bug: 119423884
Test: Boot with no-vendor-variant VNDK enabled using the new property.
Change-Id: Id808c1733c8e2c2c3462b04c72461f9698403571
diff --git a/linker/linker_namespaces.cpp b/linker/linker_namespaces.cpp
index fd72cdc..e870ef7 100644
--- a/linker/linker_namespaces.cpp
+++ b/linker/linker_namespaces.cpp
@@ -38,6 +38,14 @@
     return true;
   }
 
+  if (!whitelisted_libs_.empty()) {
+    const char *lib_name = basename(file.c_str());
+    if (std::find(whitelisted_libs_.begin(), whitelisted_libs_.end(),
+                  lib_name) == whitelisted_libs_.end()) {
+      return false;
+    }
+  }
+
   for (const auto& dir : ld_library_paths_) {
     if (file_is_in_dir(file, dir)) {
       return true;