Handle CustomTabs safely on Android

Make sure this is safe in Fenix https://github.com/mozilla-mobile/android-components/blob/v44.0.1/components/feature/customtabs/src/main/java/mozilla/components/feature/customtabs/CustomTabWindowFeature.kt#L86

And PendingIntent

https://github.com/mozilla-mobile/android-components/blob/v44.0.1/components/feature/customtabs/src/main/java/mozilla/components/feature/customtabs/CustomTabsToolbarFeature.kt#L260

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