Add actor and name parsing for overlayable

Add parsing of two overlayable attributes:
 name : The unnique identifying name of the overlayable set of resources
 actor: The component responsible for enabling and disabling overlays
        targeting the specified set of resources

Bug: 110869880
Bug: 119390855
Test: m -j aapt2_tests
Change-Id: Id42463e2b92b69034fb39cd29bc8606affb61ba7
diff --git a/tools/aapt2/link/ReferenceLinker.cpp b/tools/aapt2/link/ReferenceLinker.cpp
index 8cbc037..c2340ba 100644
--- a/tools/aapt2/link/ReferenceLinker.cpp
+++ b/tools/aapt2/link/ReferenceLinker.cpp
@@ -374,8 +374,8 @@
         }
 
         // Ensure that definitions for values declared as overlayable exist
-        if (entry->overlayable && entry->values.empty()) {
-          context->GetDiagnostics()->Error(DiagMessage(entry->overlayable.value().source)
+        if (entry->overlayable_item && entry->values.empty()) {
+          context->GetDiagnostics()->Error(DiagMessage(entry->overlayable_item.value().source)
                                            << "no definition for overlayable symbol '"
                                            << name << "'");
           error = true;