Updating a couple of docs since we can no longer accept any patches for generated files. (#2285)

* Update CONTRIBUTING.md (we no longer accept metadata patches directly)

* Update making-metadata-changes.md

* Update making-metadata-changes.md

Co-authored-by: lararennie <lararennie@users.noreply.github.com>
Co-authored-by: Tijana Vislavski Gradina <tijanavg@google.com>

CONTRIBUTING.md

@@ -96,8 +96,10 @@ license](http://github.com/google/libphonenumber/blob/master/LICENSE).**
 
 ## Pull requests
 
-We do not accept pull requests for validation, formatting, or timezone metadata
-updates.
+Since all metadata (XML and mapping files) is generated automatically from other
+sources, we cannot accept pull requests to edit these files directly. This includes
+validation, formatting, geocoding, operator or timezone metadata. However this does
+not mean you cannot raise issues for this data.
 
 For changes specific to windows builds, see [Filing a code
 issue](#filing-a-code-issue) and make sure you have found a reviewer and tester
@@ -107,8 +109,6 @@ specific to your build/setup, please prefer [creating a code bug](#filing-a-code
 
 We are happy to review and accept pull requests for the following:
 
-*   Carrier updates
-*   Geocoding updates
 *   Bug fixes
 *   Documentation and code hygiene cleanups
 

making-metadata-changes.md

@@ -5,13 +5,12 @@
 These steps outline how to edit the metadata for the phone number library to fix
 problems with validation or formatting.
 
-Note that we are currently not accepting validation, formatting, or timezone
-metadata pull requests, but you may use these guidelines to create changes in
-your own fork until we fix issues upstream. Please [file a corresponding
-issue](CONTRIBUTING.md#checklist-before-filing-an-issue) with us.
+Note that we cannot accept pull requests to modify metadata directly, but you may
+use these guidelines to create changes in your own fork until we fix issues
+upstream. Please [file a corresponding issue](CONTRIBUTING.md#checklist-before-filing-an-issue)
+with us.
 
-You can read more about the pull request [contribution
-guidelines](CONTRIBUTING.md#pull-requests).
+You can read more about the pull request [contribution guidelines](CONTRIBUTING.md#pull-requests).
 
 ## Details