Fix inconsistent inflection of API module

We have more instances of API so we change all remaining
Api definitions.

app/services/clusters/applications/base_helm_service.rb

@@ -50,7 +50,7 @@ module Clusters
       end
 
       def helm_api
-        @helm_api ||= Gitlab::Kubernetes::Helm::Api.new(kubeclient)
+        @helm_api ||= Gitlab::Kubernetes::Helm::API.new(kubeclient)
       end
 
       def install_command

ee/spec/services/clusters/applications/prometheus_update_service_spec.rb

@@ -10,7 +10,7 @@ describe Clusters::Applications::PrometheusUpdateService do
     let(:application) { create(:clusters_applications_prometheus, :installed, cluster: cluster) }
     let(:empty_alerts_values_update_yaml) { "---\nalertmanager:\n  enabled: false\nserverFiles:\n  alerts: {}\n" }
     let!(:patch_command) { application.patch_command(empty_alerts_values_update_yaml) }
-    let(:helm_client) { instance_double(::Gitlab::Kubernetes::Helm::Api) }
+    let(:helm_client) { instance_double(::Gitlab::Kubernetes::Helm::API) }
 
     subject(:service) { described_class.new(application, project) }
 

lib/gitlab/kubernetes/helm/api.rb

@@ -3,7 +3,7 @@
 module Gitlab
   module Kubernetes
     module Helm
-      class Api
+      class API
         def initialize(kubeclient)
           @kubeclient = kubeclient
           @namespace = Gitlab::Kubernetes::Namespace.new(

spec/lib/gitlab/kubernetes/helm/api_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-describe Gitlab::Kubernetes::Helm::Api do
+describe Gitlab::Kubernetes::Helm::API do
   let(:client) { double('kubernetes client') }
   let(:helm) { described_class.new(client) }
   let(:gitlab_namespace) { Gitlab::Kubernetes::Helm::NAMESPACE }

spec/services/clusters/applications/check_installation_progress_service_spec.rb

@@ -144,7 +144,7 @@ describe Clusters::Applications::CheckInstallationProgressService, '#execute' do
       end
 
       it 'removes the installation POD' do
-        expect_next_instance_of(Gitlab::Kubernetes::Helm::Api) do |instance|
+        expect_next_instance_of(Gitlab::Kubernetes::Helm::API) do |instance|
           expect(instance).to receive(:delete_pod!).with(kind_of(String)).once
         end
         expect(service).to receive(:remove_installation_pod).and_call_original

spec/services/clusters/applications/check_uninstall_progress_service_spec.rb

@@ -48,7 +48,7 @@ describe Clusters::Applications::CheckUninstallProgressService do
       let(:phase) { Gitlab::Kubernetes::Pod::SUCCEEDED }
 
       before do
-        expect_next_instance_of(Gitlab::Kubernetes::Helm::Api) do |instance|
+        expect_next_instance_of(Gitlab::Kubernetes::Helm::API) do |instance|
           expect(instance).to receive(:delete_pod!).with(kind_of(String)).once
         end
         expect(service).to receive(:pod_phase).once.and_return(phase)

spec/services/clusters/applications/install_service_spec.rb

@@ -7,7 +7,7 @@ describe Clusters::Applications::InstallService do
     let(:application) { create(:clusters_applications_helm, :scheduled) }
     let!(:install_command) { application.install_command }
     let(:service) { described_class.new(application) }
-    let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::Api) }
+    let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::API) }
 
     before do
       allow(service).to receive(:install_command).and_return(install_command)

spec/services/clusters/applications/patch_service_spec.rb

@@ -7,7 +7,7 @@ describe Clusters::Applications::PatchService do
     let(:application) { create(:clusters_applications_knative, :scheduled) }
     let!(:update_command) { application.update_command }
     let(:service) { described_class.new(application) }
-    let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::Api) }
+    let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::API) }
 
     before do
       allow(service).to receive(:update_command).and_return(update_command)

spec/services/clusters/applications/uninstall_service_spec.rb

@@ -5,7 +5,7 @@ require 'spec_helper'
 describe Clusters::Applications::UninstallService, '#execute' do
   let(:application) { create(:clusters_applications_prometheus, :scheduled) }
   let(:service) { described_class.new(application) }
-  let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::Api) }
+  let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::API) }
   let(:worker_class) { Clusters::Applications::WaitForUninstallAppWorker }
 
   before do

spec/services/clusters/applications/upgrade_service_spec.rb

@@ -7,7 +7,7 @@ describe Clusters::Applications::UpgradeService do
     let(:application) { create(:clusters_applications_helm, :scheduled) }
     let!(:install_command) { application.install_command }
     let(:service) { described_class.new(application) }
-    let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::Api) }
+    let(:helm_client) { instance_double(Gitlab::Kubernetes::Helm::API) }
 
     before do
       allow(service).to receive(:install_command).and_return(install_command)