Remove autocomplete for prometheus manual configs

Prometheus manual configuration form has inputs
that can have sensitive information. This MR sets
autocomplete to off for such inputs

app/models/project_services/prometheus_service.rb

@@ -74,6 +74,7 @@ class PrometheusService < MonitoringService
           name: 'google_iap_audience_client_id',
           title: 'Google IAP Audience Client ID',
           placeholder: s_('PrometheusService|Client ID of the IAP secured resource (looks like IAP_CLIENT_ID.apps.googleusercontent.com)'),
+          autocomplete: 'off',
           required: false
         },
         {

app/views/shared/_field.html.haml

@@ -3,6 +3,7 @@
 - value = @service.send(name)
 - type = field[:type]
 - placeholder = field[:placeholder]
+- autocomplete = field[:autocomplete]
 - required = field[:required]
 - choices = field[:choices]
 - default_choice = field[:default_choice]
@@ -15,7 +16,7 @@
     = form.label name, title, class: "col-form-label col-sm-2"
   .col-sm-10
     - if type == 'text'
-      = form.text_field name, class: "form-control", placeholder: placeholder, required: required, data: { qa_selector: "#{name.downcase.gsub('\s', '')}_field" }
+      = form.text_field name, class: "form-control", autocomplete: autocomplete, placeholder: placeholder, required: required, data: { qa_selector: "#{name.downcase.gsub('\s', '')}_field" }
     - elsif type == 'textarea'
       = form.text_area name, rows: 5, class: "form-control", placeholder: placeholder, required: required
     - elsif type == 'checkbox'

spec/models/project_services/prometheus_service_spec.rb

@@ -484,6 +484,7 @@ describe PrometheusService, :use_clean_rails_memory_store_caching do
           name: 'google_iap_audience_client_id',
           title: 'Google IAP Audience Client ID',
           placeholder: s_('PrometheusService|Client ID of the IAP secured resource (looks like IAP_CLIENT_ID.apps.googleusercontent.com)'),
+          autocomplete: 'off',
           required: false
         },
         {