[Bug]The onboarding flashes when you return from settings

[sv-sdeiac]

Prerequisites

You have a fresh install or clear data before.

Steps to reproduce

1. Open Firefox Preview;
2. Tap on the 3dot menu;
3. Tap on Settings;
4. Tap on back button from your device;

Expected behavior

When Back is tapped, the onboarding tour is no longer displayed.

Actual behavior

The onboarding tour is no longer displayed but has a flash close view.

Device information

• Android device: Nexus 9 (Android 7.1.1)
• Fenix version: 1.2.0-rc.1 Thursday 8/1

Notes:

• video;
• The disappearing of the onboarding should be smoother.

┆Issue is synchronized with this Jira Task

[sblatz]

Can we just hide onboarding before navigating away? Since we intend to not show the onboarding when a user moves to Settings, it seems reasonable to just hide it immediately.

[ekager]

Yep that seems like a good solution. Adding a help wanted label

[sv-ohorvath]

@ekager This is still reproducible on Nightly 190816 and RC 1.3.0 on Xiaomi Mi Pad 2 (Android 5.1) & Nexus 9 (Android 7.1.1).
Recording

[lobontiumira]

Verified as fixed on the latest Nightly 190821 (#12330640) with OnePlus 5T (Android 9), Huawei P9 Lite (Android 6.0.1), HTC Desire 820 (Android 6.0.1), Sony Xperia Z2 Tablet (Android 6.0.1), Nexus 9 (Android 7.1.1), and Sony Xperia Z5 Premium (Android 7.1.1).