Adding decimal place for time saved stats

[maazadeeb]

Fixes #6650

Time saved in hours will now have 1 decimal place. And time saved
in days will have 2 decimal places

Auditors: @bbondy @bsclifton

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Test Plan

1. Make sure all instances of Brave are closed
2. Open your session file (~/Libraries/Application Support/brave/session-state-1 on macOS, %appdata%\brave\session-state-1 on Windows) in an editor such as Sublime, vim, notepad, etc. If you have a JSON formatting plugin, you may wish to use it (so that it's easier to edit)
3. Edit the JSON foradblock > count to be 555555 (six fives)
   
4. Save the file and then launch Brave
5. Verify it shows hours with 1 decimal point of precision, like so:
   
6. Close Brave and re-open your session file in your editor of choice
7. Edit the adblock > count value to be 55555555 (eight fives)
8. Save the file and then launch Brave
9. Verify it shows the days with two digits of precision, like so:
   

[bsclifton]

Great work, @maaz93! 😄 I just tested this and it looks perfect. I added testing steps to make it easier for the manual testers.

Huge 👍 for adding the unit tests- very much appreciated 😄

[bsclifton]

@maaz93 if you're interested, another very similar issue (but more difficult) would be #5889

When testing the above and putting a HUGE number of ads in place (via my session), I noticed it overflow like so:

The actual number is 55,555,555 which may be abbreviated as 55.5 million. This issue would be more difficult because you'd need to pull the units out (or their abbreviation, like 10k for 10,000) into the locale files, so that other locales can add their appropriate name/symbol

[maazadeeb]

Thanks @bsclifton ! 😄 The issue that you've mentioned is interesting. I would like to take it up. I might need some info regarding it. I'll post it on the issue itself, after going through it.