Rewards summary is not retained between browser restarts.

Follow up from https://github.com/brave/brave-browser/issues/2332

Steps to Reproduce

1. Clean install
2. Tip a verified publisher
3. Check Rewards summery in brave://rewards
4. Restart browser
5. Check Rewards summery in brave://rewards

Actual result:

Rewards summery is empty Rewards summery is shown for given month (January on the screen shot), which indicates that all transactions are included.

Note: Tips table retains the data.

Expected result:

Rewards summery is retained

Reproduces how often:

always

Brave version (brave://version info)

Brave	0.59.26 Chromium: 72.0.3626.64 (Official Build) beta (64-bit)
Revision	eaa9668e80ce5405e7f1902579558ea725c06ca1-refs/branch-heads/3626@{#708}
OS	Windows

cc @brave/legacy_qa @NejcZdovc

[srirambv]

@kjozwiak @bbondy I’d just leave it for 0.60.x. Its not like we are losing the actual tip, restart workaround just works fine.

[kjozwiak]

Jumped on a quick call with @NejcZdovc and narrowed down the issue. This only happens when there’s only a tip being listed under Summary no other entries. Example:

Case that’s reproducible:

• launch Brave with a new profile and restore a wallet (no entries in the summary)
• tip a verified publisher and a tip entry appears in the summary (only entry)
• restart the browser and you’ll notice that the tip entry is removed

Case that’s not reproducible:

• launch Brave with a new profile and accept a grant (now there’s a grant entry in the summary)
• tip a verified publisher and a tip entry appears in the summary (now there’s two entries)
• restart the browser and you’ll notice that the tip doesn’t disappear from the summary this time