Fix regression in CNAME uncloaking

[antonok-edm]

This change accidentally modified a URL involved in CNAME uncloaking, causing uncloaked results to be ignored.

There may be some additional platform-specific issues with the DNS resolvers that prevent this change from working, but those are captured in #14755.

[kjozwiak]

This only fixes Android & macOS as per the labels. Win x64 & Linux are still displaying 1 after adding the custom filter in brave://adblock and will be addressed in a follow up issue.

[stephendonner]

Verified PASSED using the testplan from brave/brave-core#8262 on build

Brave	1.23.43 Chromium: 89.0.4389.90 (Official Build) beta (x86_64)
Revision	62eb262cdaae9ef819aadd778193781455ec7a49-refs/branch-heads/4389@{#1534}
OS	macOS Version 11.2.3 (Build 20D91)

Steps:

1. visited https://pushbullet.com (there should be 1 request being blocked)

2. added the following custom filer via brave://adblock

||stripecdn.map.fastly.net^$important
||d2rhbqunra2aep.cloudfront.net^$important

3. opened new tab
4. visited https://pushbullet.com (there should be 2 requests blocked)

[kjozwiak]

Also verified on Win x64 on Nightly via brave/brave-core#8262 (comment). The remaining part of this will be fixed via brave/brave-core#8279 which will also be uplifted.

[srirambv]

Verification passed on OnePlus 6T with Android 10 running 1.22.66 x64 build

• Verified test plan from Use cname url when blocking brave-core#8262

Before custom filters	Custom Filters	Post custom filters

---

Verification passed on Samsung Tab A with Android 10 running 1.22.66 x64 build

• Verified test plan from Use cname url when blocking brave-core#8262

Before custom filters	Custom Filters	Post custom filters