Recurring custom tips allows exponential values

[GeetaSarvadnya]

Description

Found while testing #15006
Recurring custom tips allows exponential values

Steps to Reproduce

1. Clean profile 1.25.x
2. Enable rewards and claim UGP grants
3. Open a verified publisher
4. Open tipping banner
5. Click on Custom tip amount
6. Enter a random whole number in BAT text field for recurring tips
7. Entered value isn't truncate to 2 decimal places even after clicking away from the field (inside/outside the banner)

Actual result:

Recurring custom tips allows exponential values

Expected result:

Values should be truncated to 2 decimal places

Reproduces how often:

Easy

Brave version (brave://version info)

Brave	1.25.62 Chromium: 90.0.4430.212 (Official Build) beta (64-bit)
Revision	e3cd97fc771b893b7fd1879196d1215b622c2bed-refs/branch-heads/4430@{#1429}
OS	Windows 10 OS Version 2004 (Build 19041.985)

Version/Channel Information:

• Can you reproduce this issue with the current release? NA
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the nightly channel? not sure

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? NA
• Does the issue resolve itself when disabling Brave Rewards? NA
• Is the issue reproducible on the latest version of Chrome? NA

Miscellaneous Information:

cc: @brave/legacy_qa @emerick @zenparsing @rebron

[LaurenWags]

Verified passed with

Brave | 1.25.66 Chromium: 91.0.4472.70 (Official Build) (x86_64)
-- | --
Revision | fe095368270a32c92959403754bf6fd357dd9953-refs/branch-heads/4472@{#1172}
OS | macOS Version 10.15.7 (Build 19H1030)

Verified STR from description.

Example	Example	Example

Verified that if you attempt to enter a very large USD amount (instead of entering BAT as above), you are still limited to 100 BAT:

Example	Example	Example