Can not change adsPerDay through UI

[btlechowski]

Steps to Reproduce

1. Go to brave://rewards
2. Enable rewards
3. Enable ads
4. Click on Ads Settings

Actual result:

Not possible to change adsPerDay through UI
Only possible to set adds per hour

Expected result:

Possible to change adsPerDay through UI
Which is required by the Brave Ads Client V1.0 Client spec:
Follow max ads per day and max ads per hour user settings for capping ads

Brave version (brave://version info)

Brave	0.60.13 Chromium: 72.0.3626.53 (Official Build) dev (64-bit)
Revision	98434e6cd182d68ce396daa92e9c6310422e6763-refs/branch-heads/3626@{#620}
OS	Windows

cc @mrose17 @brave/legacy_qa

[mrose17]

I am reliably informed that this is no longer a requirement. Perhaps in the future, we may bring it back!