Bp2build support for app R8-related fields

Bug: 293304784
Test: CI
Change-Id: I0aefa57f968cb41e50d7c1d29b2d8a1480655355
diff --git a/genrule/genrule.go b/genrule/genrule.go
index 8e3f278..d1c2f13 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -912,7 +912,7 @@
 	Out []string
 }
 
-type bazelGenruleAttributes struct {
+type BazelGenruleAttributes struct {
 	Srcs  bazel.LabelListAttribute
 	Outs  []string
 	Tools bazel.LabelListAttribute
@@ -1036,7 +1036,7 @@
 				break
 			}
 		}
-		attrs := &bazelGenruleAttributes{
+		attrs := &BazelGenruleAttributes{
 			Srcs:  srcs,
 			Outs:  outs,
 			Cmd:   cmdProp,