Optimise code in admin_auth_activity.xml

[MohamedMedhat1998]

This issue is tracking the optimization work of admin_auth_activity.xml

1. Make sure that the layout uses ConstraintLayout and there is minimal nesting of views. If this view already uses ConstraintLayout then it's fine.

2. Make sure that all TextViews use the style from styles.xml file like Heading1, TextFieldLabel, Body, etc. whichever suits best.

While making the above changes the UI should not get affected and the end result should still be the same as before (or an optimized version of UI).

If there are multiple files with the same name, update them all.

References

Mobile Portrait: https://xd.adobe.com/view/e8aa4198-3940-47f9-514a-f41cc54457f6-9e9b/grid/
Mobile Landscape: https://xd.adobe.com/view/ee9e607b-dbd6-4372-48dc-b687d32af3da-98af/grid/
Tablet: https://xd.adobe.com/view/d405de00-a871-4f0f-73a0-f8acef30349b-a234/grid/
Wiki: https://github.com/oppia/oppia-android/wiki/Working-on-UI

[bladebunny]

I submitted a PR that flattens the view hierarchy and uses standard (Heading2 and Subtitle1) text styles. I also made some small adjustments to the margins to be more standard. Landscape view was using a scrollview which did not appear necessary which I removed. I was not able to test completely because I wasn't sure how to get to the view through app usage. But I did verify the layouts for different sized devices in the layout editor.

See: #1963

[BenHenning]

Thanks @bladebunny. Assigning this to you.

For future issues, could you leave a message on the issue you'd like to work on so that someone else doesn't start that issue? It helps us to know who's actively working on which issues.

[FareesHussain]

please assign this to me