Remove library decorator for extracting headers

It is unused and removing it allows us to use the same function for
prebuilt/not libraries.

Test: bp2build.sh
Change-Id: I92ac56496cff2c2e55d6eb9f261fe75a1b232856
diff --git a/cc/bp2build.go b/cc/bp2build.go
index 19855fa..5c2523c 100644
--- a/cc/bp2build.go
+++ b/cc/bp2build.go
@@ -828,22 +828,7 @@
 	SystemIncludes   bazel.StringListAttribute
 }
 
-func bp2BuildParseExportedIncludes(ctx android.BazelConversionPathContext, module *Module, existingIncludes BazelIncludes) BazelIncludes {
-	libraryDecorator := module.linker.(*libraryDecorator)
-	return bp2BuildParseExportedIncludesHelper(ctx, module, libraryDecorator, &existingIncludes)
-}
-
-// Bp2buildParseExportedIncludesForPrebuiltLibrary returns a BazelIncludes with Bazel-ified values
-// to export includes from the underlying module's properties.
-func Bp2BuildParseExportedIncludesForPrebuiltLibrary(ctx android.BazelConversionPathContext, module *Module) BazelIncludes {
-	prebuiltLibraryLinker := module.linker.(*prebuiltLibraryLinker)
-	libraryDecorator := prebuiltLibraryLinker.libraryDecorator
-	return bp2BuildParseExportedIncludesHelper(ctx, module, libraryDecorator, nil)
-}
-
-// bp2BuildParseExportedIncludes creates a string list attribute contains the
-// exported included directories of a module.
-func bp2BuildParseExportedIncludesHelper(ctx android.BazelConversionPathContext, module *Module, libraryDecorator *libraryDecorator, includes *BazelIncludes) BazelIncludes {
+func bp2BuildParseExportedIncludes(ctx android.BazelConversionPathContext, module *Module, includes *BazelIncludes) BazelIncludes {
 	var exported BazelIncludes
 	if includes != nil {
 		exported = *includes