Disable rewards logs and remove existing ones

[NejcZdovc]

We should stop logging rewards and ads logs into file on the disk. We should also remove all existing logs that are there. Let's add a flag to rewards flag to enable logging, so that internal people can still enable them and audit them

[LaurenWags]

Removing QA/Blocked, this should be available to test in 1.13.78 and above.

[btlechowski]

Verification passed on

Brave	1.13.79 Chromium: 85.0.4183.69 (Official Build) dev (64-bit)
Revision	4554ea1a1171bd8d06951a4b7d9336afe6c59967-refs/branch-heads/4183@{#1426}
OS	Ubuntu 18.04 LTS

• Verified test plan from Disable logs brave-core#6439

Confirmed Rewards.log is generated on 1.12.114

Verified the log is deleted after upgrade to 1.13.x

Verified the log is not generated on clean profile

Note: Clear, Refresh and Download full log doesn't work under brave://rewards-internals

---

Verification passed on

Brave | 1.14.59 Chromium: 85.0.4183.69 (Official Build) dev (64-bit)
-- | --
Revision | 4554ea1a1171bd8d06951a4b7d9336afe6c59967-refs/branch-heads/4183@{#1426}
OS | Windows 10 OS Version 1903 (Build 18362.1016)

• Verified test plan from Disable logs brave-core#6439
• ensured that Rewards.log wasn't created under ...\AppData\Local\BraveSoftware\Brave-Browser-Dev\User Data\Default
• ensured that Clear, Refresh and Download full log doesn't work under brave://rewards-internals and doesn't crash (checked brave://crashes)
• Updated profile 1.12.x to 1.14.x, ensured that Rewards.log was removed from ...\AppData\Local\BraveSoftware\Brave-Browser-Dev\User Data\Default
• ensured there's no crashes under brave://crashes after upgrading
• ensured that Clear, Refresh and Download full log doesn't work under brave://rewards-internals and doesn't crash (checked brave://crashes)

---

Verified passed with

Brave	1.13.79 Chromium: 85.0.4183.69 (Official Build) dev (64-bit)
Revision	4554ea1a1171bd8d06951a4b7d9336afe6c59967-refs/branch-heads/4183@{#1426}
OS	macOS Version 10.14.6 (Build 18G3020)

• Verified test plan from Disable logs brave-core#6439

• For plan 1, launched above version, enabled Rewards. Confirmed no Rewards.log in profile folder. Confirmed checkbox and buttons do not work on Logs tab of brave://rewards-internals (able to click, but no logs appear in UI and Rewards.log is not generated). Confirmed no log file is created on browser relaunch either.

• For plan 2, enabled Rewards in 1.12.x and confirmed existence of Rewards.log in profile folder. Upgraded to 1.13.x (via profile renaming). Confirmed after launching 1.13.x the Rewards.log file was removed from profile folder. Confirmed checkbox and buttons do not work on Logs tab of brave://rewards-internals (able to click, but no logs appear in UI and Rewards.log is not generated). Confirmed no log file is created on browser relaunch either.

• Logged follow up issue Rewards log not deleted if Rewards are off prior to upgrade - follow up to 11260 #11372

[srirambv]

Verification passed on Samsung Tab A with Android 10 running 1.13.81 x64 build

• Verified clicking on the refresh button in brave://rewards-internals doesn't populate any logs in the view field
• Verified clicking on Download full log button does nothing. No file is downloaded

---

Verification passed on OnePlus 6T with Android 10 running 1.13.81 x64 build

• Verified clicking on the refresh button in brave://rewards-internals doesn't populate any logs in the view field
• Verified clicking on Download full log button does nothing. No file is downloaded