libsnapshot: Properly set partial_update_

On GKI updates, has_dynamic_partition_metadata() may be false. Even if
it is the case, partial_update_ should be set properly.

Test: apply GKI update
Bug: 162616968

Change-Id: Icf055d8eb3060e36b3e977541a24f62f9fe11a6f
diff --git a/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp b/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp
index 051584c..f66bded 100644
--- a/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp
+++ b/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp
@@ -39,6 +39,8 @@
 SnapshotMetadataUpdater::SnapshotMetadataUpdater(MetadataBuilder* builder, uint32_t target_slot,
                                                  const DeltaArchiveManifest& manifest)
     : builder_(builder), target_suffix_(SlotSuffixForSlotNumber(target_slot)) {
+    partial_update_ = manifest.partial_update();
+
     if (!manifest.has_dynamic_partition_metadata()) {
         return;
     }
@@ -63,7 +65,6 @@
         }
     }
 
-    partial_update_ = manifest.partial_update();
 }
 
 bool SnapshotMetadataUpdater::ShrinkPartitions() const {