fix dir creation mode

They need to be writable by owner.

Test: manual
Change-Id: I3e99094e5752c0f6bb351cc24bdf5698b7a4bde2
diff --git a/services/incremental/IncrementalService.cpp b/services/incremental/IncrementalService.cpp
index e4a37dde..b7cea1f 100644
--- a/services/incremental/IncrementalService.cpp
+++ b/services/incremental/IncrementalService.cpp
@@ -169,7 +169,7 @@
         base::StringAppendF(&name, "%.*s_%d_%d", int(constants().storagePrefix.size()),
                             constants().storagePrefix.data(), id, no);
         auto fullName = path::join(root, constants().mount, name);
-        if (auto err = incrementalService.mIncFs->makeDir(control, fullName); !err) {
+        if (auto err = incrementalService.mIncFs->makeDir(control, fullName, 0755); !err) {
             std::lock_guard l(lock);
             return storages.insert_or_assign(id, Storage{std::move(fullName)}).first;
         } else if (err != EEXIST) {