[BUG]: The Label size and Legend size values don't change when we switch between different charts

[pratibhapandey16]

What is the bug?
The Label size and Legend size values don't change when we switch between different charts

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Go to Observability/Event Analytics/Explorer page
2. Enter the query in PPL query section and select 'Year to date' option from calendar and click on 'Refresh'
3. Navigate to Visualizations page
4. Select Vertical bar chart from chart dropdown
5. Enter a valid value in Label size(e.g. 30)
6. Select Time Series chart from chart dropdown
7. Observe the issue where the value from the Vertical chart is already present for Label size
8. Repeat the above steps for Legend size

What is the expected behavior?
The Legend size and Label size values should not be same as that of earlier selected chart

@anirudha @mengweieric
cc: @abasatwar @spattnaik

[pratibhapandey16]

Bug has been fixed and tested.