Add sepolicy prebuilt directories to soong_config

These are used when we build vendor sepolicy against old plat sepolicy.

Bug: 33691272
Test: build
Change-Id: Ia4fea509a2e122f24d1669a0908c4b3d2bb3b32c
diff --git a/android/config.go b/android/config.go
index 5d90fd2..c6ebe8c 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1485,6 +1485,22 @@
 	return c.config.productVariables.BoardReqdMaskPolicy
 }
 
+func (c *deviceConfig) BoardSystemExtPublicPrebuiltDirs() []string {
+	return c.config.productVariables.BoardSystemExtPublicPrebuiltDirs
+}
+
+func (c *deviceConfig) BoardSystemExtPrivatePrebuiltDirs() []string {
+	return c.config.productVariables.BoardSystemExtPrivatePrebuiltDirs
+}
+
+func (c *deviceConfig) BoardProductPublicPrebuiltDirs() []string {
+	return c.config.productVariables.BoardProductPublicPrebuiltDirs
+}
+
+func (c *deviceConfig) BoardProductPrivatePrebuiltDirs() []string {
+	return c.config.productVariables.BoardProductPrivatePrebuiltDirs
+}
+
 func (c *deviceConfig) DirectedVendorSnapshot() bool {
 	return c.config.productVariables.DirectedVendorSnapshot
 }