Remove whitespaces when pasting contract address for adding a custom token

[srirambv]

Description

Ran in to #24721 while adding an ERC721 token on Android. When copy pasting the contract address, the cursor position doesn't clearly shows an extra space at the end which can be easily missed and can lead to issues like #24721. It would be nice to remove any whitespace when pasting the contract address

Steps to reproduce

1. Add a contract address on Slack
2. Copy contract address from Slack and try to add it
3. Autofills the contract details but doesn't add the token because there is a whitespace at the end of contract address

Actual result

Unable to add ERC721 token when there is a whitespace at the end of paste

Expected result

Remove whitespaces when pasting contract address for adding a custom token

Issue reproduces how often

Easy

Version/Channel Information:

• Can you reproduce this issue with the current Play Store version? Yes
• Can you reproduce this issue with the current Play Store Beta version? Yes
• Can you reproduce this issue with the current Play Store Nightly version? Yes

Device details

• Install type (ARM, x86): ARM
• Device type (Phone, Tablet, Phablet): All
• Android version: 12

Brave version

All

Website problems only

• 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

Additional information

cc: @Pavneet-Sing @SergeyZhukovsky @wchen342

[srirambv]

Verification passed on the following devices running 1.44.75 x64 Beta build

• Verified steps from issue description
• Verified able to add custom token when pasting contract address from clipboard

Oppo Reno (Android 12)	Samsung Tab A (Android 10)
24728-ARM.mp4	24728-Tab.mp4