Mobile schedule: Fix details and standardize "Join Video" button

[mariobehling]

Please enhance the following:

• Reduce space below speaker
• Standardize "Join Video" button, keep icon on the left (experiment to make it look good and display it in the same way in all sessions)
• Always align "Join Video" button to the top right in all sessions (as you can see in below screenshot it moved down a bit)

[iamareebjamal]

It's not hardcoded I believe, it's the session type

[mariobehling]

Yes, I got confused, because they use the track "Presentations" instead of a theme track. I took it out.

[ranjitkshah]

I think it's looking fine now or need any style changes? @mariobehling

[iamareebjamal]

See the unchecked point