TARGET_FS_CONFIG_GEN is a list, not a single path

Bug: 130787336
Test: m oemaids_header_gen oemaids_headers passwd group
Test: Set TARGET_FS_CONFIG_GEN to a list of paths
Change-Id: Ic1f7d38239f3f805ca0723c24005d3e18a811870
diff --git a/android/config.go b/android/config.go
index 0191e38..3af448d 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1053,6 +1053,6 @@
 	return c.productVariables.ProductHiddenAPIStubsTest
 }
 
-func (c *deviceConfig) TargetFSConfigGen() *string {
+func (c *deviceConfig) TargetFSConfigGen() []string {
 	return c.config.productVariables.TargetFSConfigGen
 }