Generate product variants by default

PRODUCT_PRODUCT_VNDK_VERSION is set to 'current' by default. Now, we
can generate product variants without checking the
PRODUCT_PRODUCT_VNDK_VERSION build variable. Remove reading the
PRODUCT_PRODUCT_VNDK_VERSION variable from soong and generate product
variants by default.

Bug: 302255959
Test: m
Change-Id: I9a9b2076f4367c5ce9a393bbb206f8dee3884bd8
diff --git a/cc/genrule.go b/cc/genrule.go
index d1c4c2a..63c728c 100644
--- a/cc/genrule.go
+++ b/cc/genrule.go
@@ -84,7 +84,7 @@
 		return true
 	}
 
-	if ctx.DeviceConfig().ProductVndkVersion() != "" && ctx.ProductSpecific() {
+	if ctx.ProductSpecific() {
 		return false
 	}
 
@@ -134,15 +134,8 @@
 		}
 	}
 
-	if ctx.DeviceConfig().ProductVndkVersion() == "" {
-		return variants
-	}
-
 	if Bool(g.Product_available) || ctx.ProductSpecific() {
 		variants = append(variants, ProductVariationPrefix+ctx.DeviceConfig().PlatformVndkVersion())
-		if vndkVersion := ctx.DeviceConfig().ProductVndkVersion(); vndkVersion != "current" {
-			variants = append(variants, ProductVariationPrefix+vndkVersion)
-		}
 	}
 
 	return variants