title: parameter still pending-reboot after reboot or restart
body: <p>In RDS, postgresql 9.4, I tried to upgrade some parameters in a parameter group: pg_stat_statements.track, shared_preload_libraries and track_activity_query_size. As it described, since the last two parameters are static, so I need to reboot the DB instance. But what is wired is that even I reboot or restart the instance, the parameters are still in 'pending-reboot'</p>
  
  <pre><code>&gt; C:\&gt;aws rds describe-db-parameters --db-parameter-group-name
  &gt; pcore-production - source user {
  &gt;     "Parameters": [
  &gt;         {
  &gt;             "ApplyMethod": "immediate",
  &gt;             "Description": "Selects which statements are tracked by pg_stat_sta ements.",
  &gt;             "DataType": "string",
  &gt;             "IsModifiable": true,
  &gt;             "AllowedValues": "NONE,TOP,ALL",
  &gt;             "Source": "user",
  &gt;             "ParameterValue": "ALL",
  &gt;             "ParameterName": "pg_stat_statements.track",
  &gt;             "ApplyType": "dynamic"
  &gt;         },
  &gt;         {
  &gt;             "ApplyMethod": "pending-reboot",
  &gt;             "Description": "Lists shared libraries to preload into server.",
  &gt;             "DataType": "string",
  &gt;             "IsModifiable": true,
  &gt;             "AllowedValues": "pg_stat_statements",
  &gt;             "Source": "user",
  &gt;             "ParameterValue": "pg_stat_statements",
  &gt;             "ParameterName": "shared_preload_libraries",
  &gt;             "ApplyType": "static"
  &gt;         },
  &gt;         {
  &gt;             "ApplyMethod": "pending-reboot",
  &gt;             "Description": "Sets the size reserved for pg_stat_activity.current query, in bytes.",
  &gt;             "DataType": "integer",
  &gt;             "IsModifiable": true,
  &gt;             "AllowedValues": "100-102400",
  &gt;             "Source": "user",
  &gt;             "ParameterValue": "2048",
  &gt;             "ParameterName": "track_activity_query_size",
  &gt;             "ApplyType": "static"
  &gt;         }
  &gt;     ] }
  </code></pre>