Revert "Update child rows hidden check in the anomalies table."

This reverts commit 4a7db687eea125d4e12f6b659c040df5a335f413.

Reason for revert: The logic was incorrect. Revert the change

Original change's description:
> Update child rows hidden check in the anomalies table.
>
> The single child row was hidden in the anomalies table.
>
>
> Change-Id: I7668470ae9b235b95f46d4882234454c23d4ee7a
> Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/1022423
> Reviewed-by: Eduardo Yap <eduardoyap@google.com>
> Commit-Queue: Maggie Dong <jiaxindong@google.com>

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I0fd3fbf5ad136ceb5e4bc98022d02010bd0b1773
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/1023216
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Maggie Dong <jiaxindong@google.com>
diff --git a/perf/modules/anomalies-table-sk/anomalies-table-sk.ts b/perf/modules/anomalies-table-sk/anomalies-table-sk.ts
index a194425..edfa658 100644
--- a/perf/modules/anomalies-table-sk/anomalies-table-sk.ts
+++ b/perf/modules/anomalies-table-sk/anomalies-table-sk.ts
@@ -299,8 +299,7 @@
           data-delta="${anomalySortValues.delta}"
           class=${this.getRowClass(i + 1, anomalyGroup)}
           ?hidden=${
-            (!this.isParentRow && !anomalyGroup.expanded) ||
-            (anomalyGroup.anomalies.length > 1 && !anomalyGroup.expanded)
+            !anomalyGroup.expanded && !this.isParentRow && anomalyGroup.anomalies.length > 1
           }>
           <td>
           </td>