reconcile uses user-added BAT instead of UGP BAT

[LaurenWags]

Description

Contributions are using user-added BAT instead of UGP BAT when there is enough UGP BAT to be used.

Test Plan/Steps to Reproduce

1. Launch Brave from CLI using LEDGER_ENVIRONMENT=staging LEDGER_VERBOSE=true and enable Payments.
2. Add some sites to ledger.
3. Add 10 BAT to staging wallet.
4. Accept UGP grant. You should now have 20 BAT total in your wallet.
5. Verify monthly budget is 10BAT.
6. Close Brave.
7. Update reconcile stamp.
8. Launch Brave from CLI using LEDGER_ENVIRONMENT=staging LEDGER_VERBOSE=true LEDGER_NO_FUZZING=true LEDGER_NO_DELAY=true
9. Wait for a contribution to occur.

Actual result:
Contribution occurs. BAT used for contribution was user added:

Expected result:
BAT used for contribution should have been the UGP BAT.

Reproduces how often:
easily

Brave Version

about:brave info:
0.22.723

Reproducible on current live release:
unknown

Additional Information

Reproduced on Win by @GeetaSarvadnya

cc @evq

[LaurenWags]

Closing per discussion with @evq - should be resolved on staging.

[srirambv]

Verified on Windows x64 using

• 0.22.724 1f07e93
• muon 6.0.12
• libchromiumcontent 66.0.3359.170

Verified with Windows 10 x64 using

• 0.22.725 e6dd17f
• muon 6.0.12
• libchromiumcontent 66.0.3359.170

Verified with macOS 10.12.6 using

• 0.22.725 e6dd17f
• muon 6.0.12
• libchromiumcontent 66.0.3359.170

Verified on Ubuntu 18.04 x64 using the following build:

• 0.22.725 e6dd17f
• muon: 6.0.12
• libchromiumcontent: 66.0.3359.170