[Tests] update expected value for percentile ranks

Origin:
opensearch-project/OpenSearch#3634

The previous value was actually incorrect after OpenSearch bumped t-digest
the value is now the correct value.

Issue:
opensearch-project#1821

Signed-off-by: Kawika Avilla <kavilla414@gmail.com>

test/functional/apps/visualize/_metric_chart.js

@@ -151,7 +151,7 @@ export default function ({ getService, getPageObjects }) {
         '1st percentile of machine.ram',
         '3,221,225,472',
         '5th percentile of machine.ram',
-        '7,516,192,768',
+        '7,480,933,587.906',
         '25th percentile of machine.ram',
         '12,884,901,888',
         '50th percentile of machine.ram',
@@ -175,7 +175,7 @@ export default function ({ getService, getPageObjects }) {
     });
 
     it('should show Percentile Ranks', async function () {
-      const percentileRankBytes = ['2.036%', 'Percentile rank 99 of "memory"'];
+      const percentileRankBytes = ['2.029%', 'Percentile rank 99 of "memory"'];
       log.debug('Aggregation = Percentile Ranks');
       await PageObjects.visEditor.selectAggregation('Percentile Ranks', 'metrics');
       log.debug('Field =  bytes');