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/common/error_code.h b/common/error_code.h
index 3dd7402..1edbba3 100644
--- a/common/error_code.h
+++ b/common/error_code.h
@@ -83,6 +83,7 @@
   kInternalLibCurlError = 57,
   kUnresolvedHostError = 58,
   kUnresolvedHostRecovered = 59,
+  kNotEnoughSpace = 60,
 
   // VERY IMPORTANT! When adding new error codes:
   //