Prevent user from getting stuck on opt in page (#9856)

Failed metric events on the opt-in page no longer leave the user stuck
on that page. If the metric events fail, they still bubble up as errors
to be caught by Sentry and logged to the console, but the user is still
brought to the next page.

Fixes #9800

ui/app/pages/first-time-flow/metametrics-opt-in/metametrics-opt-in.component.js

@@ -101,57 +101,59 @@ export default class MetaMetricsOptIn extends Component {
           </div>
           <div className="metametrics-opt-in__footer">
             <PageContainerFooter
-              onCancel={() => {
-                setParticipateInMetaMetrics(false).then(() => {
-                  const promise =
-                    participateInMetaMetrics === true
-                      ? metricsEvent({
-                          eventOpts: {
-                            category: 'Onboarding',
-                            action: 'Metrics Option',
-                            name: 'Metrics Opt Out',
-                          },
-                          isOptIn: true,
-                        })
-                      : Promise.resolve()
+              onCancel={async () => {
+                await setParticipateInMetaMetrics(false)
 
-                  promise.then(() => {
-                    history.push(nextRoute)
-                  })
-                })
+                try {
+                  if (participateInMetaMetrics === true) {
+                    await metricsEvent({
+                      eventOpts: {
+                        category: 'Onboarding',
+                        action: 'Metrics Option',
+                        name: 'Metrics Opt Out',
+                      },
+                      isOptIn: true,
+                    })
+                  }
+                } finally {
+                  history.push(nextRoute)
+                }
               }}
               cancelText={t('noThanks')}
               hideCancel={false}
-              onSubmit={() => {
-                setParticipateInMetaMetrics(true).then(([_, metaMetricsId]) => {
-                  const promise =
-                    participateInMetaMetrics === false
-                      ? metricsEvent({
-                          eventOpts: {
-                            category: 'Onboarding',
-                            action: 'Metrics Option',
-                            name: 'Metrics Opt In',
-                          },
-                          isOptIn: true,
-                        })
-                      : Promise.resolve()
-
-                  promise
-                    .then(() => {
-                      return metricsEvent({
+              onSubmit={async () => {
+                const [, metaMetricsId] = await setParticipateInMetaMetrics(
+                  true,
+                )
+                try {
+                  const metrics = []
+                  if (participateInMetaMetrics === false) {
+                    metrics.push(
+                      metricsEvent({
                         eventOpts: {
                           category: 'Onboarding',
-                          action: 'Import or Create',
-                          name: firstTimeSelectionMetaMetricsName,
+                          action: 'Metrics Option',
+                          name: 'Metrics Opt In',
                         },
                         isOptIn: true,
-                        metaMetricsId,
-                      })
-                    })
-                    .then(() => {
-                      history.push(nextRoute)
-                    })
-                })
+                      }),
+                    )
+                  }
+                  metrics.push(
+                    metricsEvent({
+                      eventOpts: {
+                        category: 'Onboarding',
+                        action: 'Import or Create',
+                        name: firstTimeSelectionMetaMetricsName,
+                      },
+                      isOptIn: true,
+                      metaMetricsId,
+                    }),
+                  )
+                  await Promise.all(metrics)
+                } finally {
+                  history.push(nextRoute)
+                }
               }}
               submitText={t('affirmAgree')}
               submitButtonType="primary"