Update pagespeedonline_v5 percentile

The 75th percentile is chosen for all metrics in pagespeed v5
https://developers.google.com/speed/docs/insights/v5/about#why-is-the-75th-percentile-chosen-for-all-metrics

docs/dyn/pagespeedonline_v5.pagespeedapi.html

@@ -363,7 +363,7 @@ <h3>Method Details</h3>
         &quot;formFactor&quot;: &quot;A String&quot;, # Identifies the form factor of the metric being collected.
         &quot;median&quot;: 42, # The median number of the metric, in millisecond.
         &quot;metricId&quot;: &quot;A String&quot;, # Identifies the type of the metric.
-        &quot;percentile&quot;: 42, # We use this field to store certain percentile value for this metric. For v4, this field contains pc50. For v5, this field contains pc90.
+        &quot;percentile&quot;: 42, # We use this field to store certain percentile value for this metric. For v4, this field contains pc50. For v5, this field contains pc75.
       },
     },
     &quot;origin_fallback&quot;: True or False, # True if the result is an origin fallback from a page, false otherwise.
@@ -385,7 +385,7 @@ <h3>Method Details</h3>
         &quot;formFactor&quot;: &quot;A String&quot;, # Identifies the form factor of the metric being collected.
         &quot;median&quot;: 42, # The median number of the metric, in millisecond.
         &quot;metricId&quot;: &quot;A String&quot;, # Identifies the type of the metric.
-        &quot;percentile&quot;: 42, # We use this field to store certain percentile value for this metric. For v4, this field contains pc50. For v5, this field contains pc90.
+        &quot;percentile&quot;: 42, # We use this field to store certain percentile value for this metric. For v4, this field contains pc50. For v5, this field contains pc75.
       },
     },
     &quot;origin_fallback&quot;: True or False, # True if the result is an origin fallback from a page, false otherwise.
@@ -398,4 +398,4 @@ <h3>Method Details</h3>
 }</pre>
 </div>
 
-</body></html>
+</body></html>