Hide preview charts in APM rules (elastic#156966)

Hides preview charts in the following APM rules until
elastic#156625 (WIP) gets merged.

- APM Latency threshold
- APM Failed transaction rate
- APM Error count threshold

(cherry picked from commit d10c48b)

x-pack/plugins/apm/public/components/alerting/rule_types/error_count_rule_type/index.tsx

@@ -162,14 +162,16 @@ export function ErrorCountRuleType(props: Props) {
     />,
   ];
 
-  const chartPreview = (
+  // hide preview chart until https://github.com/elastic/kibana/pull/156625 gets merged
+  const showChartPreview = false;
+  const chartPreview = showChartPreview ? (
     <ChartPreview
       series={[{ data: data?.errorCountChartPreview ?? [] }]}
       threshold={params.threshold}
       yTickFormat={asInteger}
       uiSettings={services.uiSettings}
     />
-  );
+  ) : null;
 
   const groupAlertsBy = (
     <>

x-pack/plugins/apm/public/components/alerting/rule_types/transaction_duration_rule_type/index.tsx

@@ -147,14 +147,16 @@ export function TransactionDurationRuleType(props: Props) {
   // The threshold from the form is in ms. Convert to µs.
   const thresholdMs = params.threshold * 1000;
 
-  const chartPreview = (
+  // hide preview chart until https://github.com/elastic/kibana/pull/156625 gets merged
+  const showChartPreview = false;
+  const chartPreview = showChartPreview ? (
     <ChartPreview
       series={latencyChartPreview}
       threshold={thresholdMs}
       yTickFormat={yTickFormat}
       uiSettings={services.uiSettings}
     />
-  );
+  ) : null;
 
   const onGroupByChange = useCallback(
     (group: string[] | null) => {

x-pack/plugins/apm/public/components/alerting/rule_types/transaction_error_rate_rule_type/index.tsx

@@ -171,14 +171,16 @@ export function TransactionErrorRateRuleType(props: Props) {
     />,
   ];
 
-  const chartPreview = (
+  // hide preview chart until https://github.com/elastic/kibana/pull/156625 gets merged
+  const showChartPreview = false;
+  const chartPreview = showChartPreview ? (
     <ChartPreview
       series={[{ data: data?.errorRateChartPreview ?? [] }]}
       yTickFormat={(d: number | null) => asPercent(d, 1)}
       threshold={thresholdAsPercent}
       uiSettings={services.uiSettings}
     />
-  );
+  ) : null;
 
   const groupAlertsBy = (
     <>