Use sentence casing in some settings

[brishtibheja]

If you go to Settings>>Controls then a few inconsistencies appear in capitalisation. The ones that I could spot are:

1. F in Flag is capitalised when it should be not.
2. W in Toggle Whiteboard is capitalised but other instances of whiteboard in the same screen are not.
3. L is not capitalised in Abort learning when it is in Abort Learning and Sync.