Disabling Rewards should also disable Ads

[ryanml]

Description

Disabling Rewards via the main toggle under brave://rewards should also disable Ads

Steps to Reproduce

1. Enable Rewards
2. If not automatically enabled, enable Ads.
3. Verify you see some Ads after some time browsing
4. Turn off Rewards (do not explicitly turn off Ads)

Actual result:

Ads is still enabled and notifications are still delivered

Expected result:

Ads should be disabled

Reproduces how often:

Brave version (brave://version info)

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds?

Website problems only:

• Does the issue resolve itself when disabling Brave Shields?
• Is the issue reproducible on the latest version of Chrome?

Additional Information

[NejcZdovc]

I think this needs to be fixed in ads library to check if rewards are enabled or not

[NejcZdovc]

we do the same thing with everything else cc @bridiver @tmancey

[ryanml]

Fixed with: brave/brave-core#1297

[LaurenWags]

Verified passed with

Brave	0.60.28 Chromium: 72.0.3626.96 (Official Build) beta(64-bit)
Revision	84098ee7ef8622a9defc2ef043cd8930b617b10e-refs/branch-heads/3626@{#836}
OS	Mac OS X

• Verified test plan in Fixes rewards disabled for ads brave-core#1297
• Additional testing notes outlined here: Ad notifications sometimes presented to user when Ads toggle is off #2972 (comment)

Verification passed on

Brave	0.60.29 Chromium: 72.0.3626.96 (Official Build) beta (64-bit)
Revision	84098ee7ef8622a9defc2ef043cd8930b617b10e-refs/branch-heads/3626@{#836}
OS	Windows 7

Used test plan from brave/brave-core#1297