Fix error messages during dashboard manage action

Change error messages to more action oriented and avoid encoded
characters. For dashboard clone and update actions.

app/services/metrics/dashboard/clone_dashboard_service.rb

@@ -24,7 +24,7 @@ module Metrics
 
       def execute
         catch(:error) do
-          throw(:error, error(_(%q(You can't commit to this project)), :forbidden)) unless push_authorized?
+          throw(:error, error(_(%q(You are not allowed to push into this branch. Create another branch or open a merge request.)), :forbidden)) unless push_authorized?
 
           result = ::Files::CreateService.new(project, current_user, dashboard_attrs).execute
           throw(:error, wrap_error(result)) unless result[:status] == :success

app/services/metrics/dashboard/update_dashboard_service.rb

@@ -9,7 +9,7 @@ module Metrics
 
       def execute
         catch(:error) do
-          throw(:error, error(_(%q(You can't commit to this project)), :forbidden)) unless push_authorized?
+          throw(:error, error(_(%q(You are not allowed to push into this branch. Create another branch or open a merge request.)), :forbidden)) unless push_authorized?
 
           result = ::Files::UpdateService.new(project, current_user, dashboard_attrs).execute
           throw(:error, result.merge(http_status: :bad_request)) unless result[:status] == :success

changelogs/unreleased/mwaw-197871-improve-duplicated-dashboard-error-messages.yml

+---
+title: Fix error messages for dashboard clonning process.
+merge_request: 26290
+author:
+type: fixed

locale/gitlab.pot

@@ -22440,6 +22440,9 @@ msgstr ""
 msgid "You are going to transfer %{project_full_name} to another owner. Are you ABSOLUTELY sure?"
 msgstr ""
 
+msgid "You are not allowed to push into this branch. Create another branch or open a merge request."
+msgstr ""
+
 msgid "You are not allowed to unlink your primary login account"
 msgstr ""
 
@@ -22560,9 +22563,6 @@ msgstr ""
 msgid "You can try again using %{begin_link}basic search%{end_link}"
 msgstr ""
 
-msgid "You can't commit to this project"
-msgstr ""
-
 msgid "You cannot access the raw file. Please wait a minute."
 msgstr ""
 

spec/services/metrics/dashboard/clone_dashboard_service_spec.rb

@@ -29,7 +29,7 @@ describe Metrics::Dashboard::CloneDashboardService, :use_clean_rails_memory_stor
     end
 
     context 'user does not have push right to repository' do
-      it_behaves_like 'misconfigured dashboard service response', :forbidden, %q(You can't commit to this project)
+      it_behaves_like 'misconfigured dashboard service response', :forbidden, %q(You are not allowed to push into this branch. Create another branch or open a merge request.)
     end
 
     context 'with rights to push to the repository' do

spec/services/metrics/dashboard/update_dashboard_service_spec.rb

@@ -27,7 +27,7 @@ describe Metrics::Dashboard::UpdateDashboardService, :use_clean_rails_memory_sto
     end
 
     context 'user does not have push right to repository' do
-      it_behaves_like 'misconfigured dashboard service response', :forbidden, "You can't commit to this project"
+      it_behaves_like 'misconfigured dashboard service response', :forbidden, "You are not allowed to push into this branch. Create another branch or open a merge request."
     end
 
     context 'with rights to push to the repository' do