Fix discrepancy between status names (open-telemetry#385)

Fixes open-telemetry#384

Co-authored-by: Sergey Kanzhelev <[email protected]>
Co-authored-by: Bogdan Drutu <[email protected]>

Author: 3 people

specification/api-tracing.md

@@ -473,7 +473,7 @@ codes](https://github.com/grpc/grpc/blob/master/doc/statuscodes.md):
   - The operation completed successfully.
 - `Cancelled`
   - The operation was cancelled (typically by the caller).
-- `UnknownError`
+- `Unknown`
   - An unknown error.
 - `InvalidArgument`
   - Client specified an invalid argument. Note that this differs from
@@ -506,7 +506,7 @@ codes](https://github.com/grpc/grpc/blob/master/doc/statuscodes.md):
     fixed if the system state changes.
 - `Unimplemented`
   - Operation is not implemented or not supported/enabled in this service.
-- `InternalError`
+- `Internal`
   - Internal errors. Means some invariants expected by underlying system has been
     broken.
 - `Unavailable`

specification/data-http.md

@@ -49,8 +49,8 @@ Don't set a status message if the reason can be inferred from `http.status_code`
 | 501 Not Implemented     | `Unimplemented`       |
 | 503 Service Unavailable | `Unavailable`         |
 | 504 Gateway Timeout     | `DeadlineExceeded`    |
-| Other 5xx code          | `InternalError` [1]   |
-| Any status code the client fails to interpret (e.g., 093 or 573) | `UnknownError` |
+| Other 5xx code          | `Internal` [1]   |
+| Any status code the client fails to interpret (e.g., 093 or 573) | `Unknown` |
 
 Note that the items marked with [1] are different from the mapping defined in the [OpenCensus semantic conventions][oc-http-status].
 
@@ -102,14 +102,14 @@ For status, the following special cases have canonical error codes assigned:
 
 | Client error                | Trace status code  |
 |-----------------------------|--------------------|
-| DNS resolution failed       | `UnknownError`     |
+| DNS resolution failed       | `Unknown`     |
 | Request cancelled by caller | `Cancelled`        |
 | URL cannot be parsed        | `InvalidArgument`  |
 | Request timed out           | `DeadlineExceeded` |
 
 This is not meant to be an exhaustive list
 but if there is no clear mapping for some error conditions,
-instrumentation developers are encouraged to use `UnknownError`
+instrumentation developers are encouraged to use `Unknown`
 and open a PR or issue in the specification repository.
 
 ## HTTP server
@@ -238,4 +238,4 @@ If set, it would be
 `"https://example.com:8080/webshop/articles/4?s=1"`
 but due to `http.scheme`, `http.host` and `http.target` being set, it would be redundant.
 As explained above, these separate values are preferred but if for some reason the URL is available but the other values are not,
-URL can replace `http.scheme`, `http.host` and `http.target`.
+URL can replace `http.scheme`, `http.host` and `http.target`.