Additional heuristics: variables with names ending with _LIST are lists

Bug: 193540681
Test: internal
Change-Id: Ic23bf0f0eadb159285650f0b7e20307788c12387
diff --git a/mk2rbc/mk2rbc_test.go b/mk2rbc/mk2rbc_test.go
index 46212ee..ca7fe6f 100644
--- a/mk2rbc/mk2rbc_test.go
+++ b/mk2rbc/mk2rbc_test.go
@@ -414,7 +414,7 @@
 
 def init(g, handle):
   cfg = rblf.cfg(handle)
-  if rblf.filter(g.get("PRODUCT_LIST", ""), g["TARGET_PRODUCT"]):
+  if rblf.filter(g.get("PRODUCT_LIST", []), g["TARGET_PRODUCT"]):
     pass
 `,
 	},
diff --git a/mk2rbc/variable.go b/mk2rbc/variable.go
index 88d63c9..4bb9ed5 100644
--- a/mk2rbc/variable.go
+++ b/mk2rbc/variable.go
@@ -299,6 +299,10 @@
 					vt = vi.valueType
 				}
 			}
+			if strings.HasSuffix(name, "_LIST") && vt == starlarkTypeUnknown {
+				// Heuristics: Variables with "_LIST" suffix are lists
+				vt = starlarkTypeList
+			}
 			v = &otherGlobalVariable{baseVariable{nam: name, typ: vt}}
 		}
 		ctx.variables[name] = v