[Android] The "Log in" screen is wrongly redisplayed if the app was changed from split view to full screen while logging in

[Softvision-MariusComan]

[Affected Platforms]:

• Android 8.0.0 (Google Pixel)
• Android 8.0.0 (Samsung S8)

[Prerequisites]:

• Have the latest version of the "Firefox Notes" application (app-release-signed) custom built on 7/31/2018 installed.
• You are not logged into "Firefox Notes".
• Have valid "Firefox Account" credentials.

[Steps to reproduce]:

1. Open the Notes application and put the app in the split screen view.
2. Tap the "Sign In" button and change the app's view mode to the whole screen.
3. Sign in using the credentials from prerequisites.
4. Observe the behavior.

[Expected result]:

• You are successfully logged in and the list view is displayed.

[Actual result]:

• You are successfully logged in but the "Log In" screen is displayed.

[Notes]:

• This issue is no longer reproducible after the app is reopened.
• This issue is not reproducible at "Sign Up".
• Attached a screen recording of the issue: