DynamicPartitionControl: Add required_size to Prepare

Add out parameter required_size to PreparePartitionsForUpdate
to indicate the total size required on /userdata in order
to apply the update.

Bug: 138808058
Test: update_engine_unittests

Change-Id: I2768d13671e212fd24a1a22811b50c9738834459
diff --git a/payload_consumer/delta_performer.cc b/payload_consumer/delta_performer.cc
index c49474c..8cec076 100644
--- a/payload_consumer/delta_performer.cc
+++ b/payload_consumer/delta_performer.cc
@@ -951,7 +951,8 @@
           boot_control_->GetCurrentSlot(),
           install_plan_->target_slot,
           manifest_,
-          !metadata_updated)) {
+          !metadata_updated,
+          nullptr /* required_size */)) {
     LOG(ERROR) << "Unable to initialize partition metadata for slot "
                << BootControlInterface::SlotName(install_plan_->target_slot);
     return false;