Wrong date of the first monthly tip on the monthly tip confirmation dialog

[btlechowski]

Follow up from #3023

Steps to Reproduce

1. Clean profile
2. Enable rewards
3. Claim Grant
4. Make a recurring tip on a site

Actual result:

Your first monthly tip will be sent on shows current date

Expected result:

Your first monthly tip will be sent on shows Next monthly tip date from brave://rewards/

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave	0.61.37 Chromium: 73.0.3683.39 (Official Build) beta (64-bit)
Revision	cc53b0e12fcaf42e4bab8d6c23bd4fb7aae99f6c-refs/branch-heads/3683@{#413}
OS	Windows 7 Service Pack 1 Build 7601.24312

cc @brave/legacy_qa @NejcZdovc @ryanml

[kjozwiak]

Reproduced on macOS 10.14.3 x64 using the following build:

Brave	0.61.38 Chromium: 73.0.3683.39 (Official Build) beta(64-bit)
Revision	cc53b0e12fcaf42e4bab8d6c23bd4fb7aae99f6c-refs/branch-heads/3683@{#413}
OS	Mac OS X

Example of the issue occurring on macOS (notice the inconsistent contribution dates):

[rebron]

@NejcZdovc can you ask for uplift to 61.x/62.x?

[GeetaSarvadnya]

Verification passed on

Brave	0.61.48 Chromium: 73.0.3683.56 (Official Build) beta (64-bit)
Revision	303af44e2f2948869279f120021c778855d76ead-refs/branch-heads/3683@{#653}
OS	Windows 10 OS Build 17134.523

• Verified the test plan from Fixes date for recurring banner brave-core#1789
• Verified the STR mentioned in the description

Verification PASSED on macOS 10.14.3 x64 using the following build:

Brave	0.61.48 Chromium: 73.0.3683.56 (Official Build) beta(64-bit)
Revision	303af44e2f2948869279f120021c778855d76ead-refs/branch-heads/3683@{#653}
OS	Mac OS X

• Went through the test plan outlined under Fixes date for recurring banner brave-core#1789
  • also checked YT, Twitch and websites to make sure the date was correctly being displayed

Verification passed on

Brave	0.61.49 Chromium: 73.0.3683.67 (Official Build) (64-bit)
Revision	a83fd4f3207ae83412d329a9ca1239dd1e068345-refs/branch-heads/3683@{#760}
OS	Linux mint

• Verified the test plan from Fixes date for recurring banner brave-core#1789
• Verified the STR mentioned in the description