Add ErrorCode::kNotEnoughSpace.

Virtual A/B now requires space in userdata, which may not be enough
during OTA. A kNotEnoughSpace error code is added to indicate such case.

Bug: 138808328
Test: builds

Change-Id: I6bf7964911c8eb3b9df9b8752018925a99876d0f
diff --git a/update_manager/chromeos_policy.cc b/update_manager/chromeos_policy.cc
index 8056f06..22e5094 100644
--- a/update_manager/chromeos_policy.cc
+++ b/update_manager/chromeos_policy.cc
@@ -152,6 +152,7 @@
     case ErrorCode::kInternalLibCurlError:
     case ErrorCode::kUnresolvedHostError:
     case ErrorCode::kUnresolvedHostRecovered:
+    case ErrorCode::kNotEnoughSpace:
       LOG(INFO) << "Not changing URL index or failure count due to error "
                 << chromeos_update_engine::utils::ErrorCodeToString(err_code)
                 << " (" << static_cast<int>(err_code) << ")";