Disable avb for userdata partition

To make the behavior identical between make and soong.

Test: m out/soong/.intermediates/build/soong/fsgen/aosp_cf_x86_64_phone_generated_userdata_image/android_common/userdata.img
Bug: 388920173
Change-Id: I4b89be5c0f5355b63791dde77278217f3a82318e
diff --git a/fsgen/filesystem_creator.go b/fsgen/filesystem_creator.go
index a4c008d..9aed460 100644
--- a/fsgen/filesystem_creator.go
+++ b/fsgen/filesystem_creator.go
@@ -381,6 +381,8 @@
 				panic(fmt.Sprintf("Partition size must be an int, got %s", vars.BoardPartitionSize))
 			}
 			fsProps.Partition_size = &parsed
+			// Disable avb for userdata partition
+			fsProps.Use_avb = nil
 		}
 		// https://cs.android.com/android/platform/superproject/main/+/main:build/make/core/Makefile;l=2265;drc=7f50a123045520f2c5e18e9eb4e83f92244a1459
 		if s, err := strconv.ParseBool(partitionVars.ProductFsCasefold); err == nil {
diff --git a/fsgen/vbmeta_partitions.go b/fsgen/vbmeta_partitions.go
index 11c5759..d146cbb 100644
--- a/fsgen/vbmeta_partitions.go
+++ b/fsgen/vbmeta_partitions.go
@@ -154,8 +154,8 @@
 			// Already handled by a chained vbmeta partition
 			continue
 		}
-		if strings.Contains(partitionType, "ramdisk") || strings.Contains(partitionType, "boot") {
-			// ramdisk is never signed with avb information
+		if strings.Contains(partitionType, "ramdisk") || strings.Contains(partitionType, "boot") || partitionType == "userdata" {
+			// ramdisk and userdata are never signed with avb information
 			// boot partitions just have the avb footer, and don't have a corresponding vbmeta
 			// partition.
 			continue