Add ErrorCode::kDeviceCorrupted.

This error code indicates the device is corrupted in a way
that it can no longer receive any future updates. Specifically, if a
device encounters a merge error, there is no way we can recover that
device.

Test: pass
Bug: 138808328

Change-Id: Idbd9d1bc5bc02bbba157f17f31b2c5ace839243c
diff --git a/common/error_code.h b/common/error_code.h
index 1edbba3..e473a05 100644
--- a/common/error_code.h
+++ b/common/error_code.h
@@ -84,6 +84,7 @@
   kUnresolvedHostError = 58,
   kUnresolvedHostRecovered = 59,
   kNotEnoughSpace = 60,
+  kDeviceCorrupted = 61,
 
   // VERY IMPORTANT! When adding new error codes:
   //