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.h b/linker/linker_namespaces.h
index cd8b09d..31aeeb6 100644
--- a/linker/linker_namespaces.h
+++ b/linker/linker_namespaces.h
@@ -110,6 +110,16 @@
     permitted_paths_ = permitted_paths;
   }
 
+  const std::vector<std::string>& get_whitelisted_libs() const {
+    return whitelisted_libs_;
+  }
+  void set_whitelisted_libs(std::vector<std::string>&& whitelisted_libs) {
+    whitelisted_libs_ = whitelisted_libs;
+  }
+  void set_whitelisted_libs(const std::vector<std::string>& whitelisted_libs) {
+    whitelisted_libs_ = whitelisted_libs;
+  }
+
   const std::vector<android_namespace_link_t>& linked_namespaces() const {
     return linked_namespaces_;
   }
@@ -157,6 +167,7 @@
   std::vector<std::string> ld_library_paths_;
   std::vector<std::string> default_library_paths_;
   std::vector<std::string> permitted_paths_;
+  std::vector<std::string> whitelisted_libs_;
   // Loader looks into linked namespace if it was not able
   // to find a library in this namespace. Note that library
   // lookup in linked namespaces are limited by the list of