Add ab_ota_partitions prop to android_device

This will be used to generate ab_partitions.txt file in
target_files.zip

Test: Built soong target_files.zip locally
Bug: 388633394
Change-Id: I442c0907094abb4f68fb0c666efae52509aa9538
diff --git a/fsgen/filesystem_creator.go b/fsgen/filesystem_creator.go
index 2c2da17..9217e1c 100644
--- a/fsgen/filesystem_creator.go
+++ b/fsgen/filesystem_creator.go
@@ -381,8 +381,9 @@
 	partitionProps.Vbmeta_partitions = vbmetaPartitions
 
 	deviceProps := &filesystem.DeviceProperties{
-		Main_device:    proptools.BoolPtr(true),
-		Ab_ota_updater: proptools.BoolPtr(ctx.Config().ProductVariables().PartitionVarsForSoongMigrationOnlyDoNotUse.AbOtaUpdater),
+		Main_device:       proptools.BoolPtr(true),
+		Ab_ota_updater:    proptools.BoolPtr(ctx.Config().ProductVariables().PartitionVarsForSoongMigrationOnlyDoNotUse.AbOtaUpdater),
+		Ab_ota_partitions: ctx.Config().ProductVariables().PartitionVarsForSoongMigrationOnlyDoNotUse.AbOtaPartitions,
 	}
 	if bootloader, ok := f.createBootloaderFilegroup(ctx); ok {
 		deviceProps.Bootloader = proptools.StringPtr(":" + bootloader)