Rename validate method to align with other checker class

BaseChecker uses validate instead of exec

lib/gitlab/checks/snippet_check.rb

@@ -20,14 +20,11 @@ module Gitlab
         @logger.append_message("Running checks for ref: #{@branch_name || @tag_name}")
       end
 
-      def exec
+      def validate!
         if creation? || deletion?
           raise GitAccess::ForbiddenError, ERROR_MESSAGES[:create_delete_branch]
         end
 
-        # TODO: https://gitlab.com/gitlab-org/gitlab/issues/205628
-        # Check operation will not result in more than one file in the repository
-
         true
       end
 

lib/gitlab/git_access_snippet.rb

@@ -97,9 +97,7 @@ module Gitlab
     end
 
     def check_single_change_access(change)
-      change_access = Checks::SnippetCheck.new(change, logger: logger)
-
-      change_access.exec
+      Checks::SnippetCheck.new(change, logger: logger).validate!
     rescue Checks::TimedLogger::TimeoutError
       raise TimeoutError, logger.full_message
     end

spec/lib/gitlab/checks/snippet_check_spec.rb

@@ -10,16 +10,16 @@ describe Gitlab::Checks::SnippetCheck do
 
   subject { Gitlab::Checks::SnippetCheck.new(changes, logger: logger) }
 
-  describe '#exec' do
+  describe '#validate!' do
     it 'does not raise any error' do
-      expect { subject.exec }.not_to raise_error
+      expect { subject.validate! }.not_to raise_error
     end
 
     context 'trying to delete the branch' do
       let(:newrev) { '0000000000000000000000000000000000000000' }
 
       it 'raises an error' do
-        expect { subject.exec }.to raise_error(Gitlab::GitAccess::ForbiddenError, 'You can not create or delete branches.')
+        expect { subject.validate! }.to raise_error(Gitlab::GitAccess::ForbiddenError, 'You can not create or delete branches.')
       end
     end
 
@@ -28,14 +28,14 @@ describe Gitlab::Checks::SnippetCheck do
       let(:ref) { 'refs/heads/feature' }
 
       it 'raises an error' do
-        expect { subject.exec }.to raise_error(Gitlab::GitAccess::ForbiddenError, 'You can not create or delete branches.')
+        expect { subject.validate! }.to raise_error(Gitlab::GitAccess::ForbiddenError, 'You can not create or delete branches.')
       end
 
       context "when branch is 'master'" do
         let(:ref) { 'refs/heads/master' }
 
         it "allows the operation" do
-          expect { subject.exec }.not_to raise_error
+          expect { subject.validate! }.not_to raise_error
         end
       end
     end