Fix: Resolve incorrect validation message on invalid phone number

[abhigurjeet]

Description

On Customer page, when we try to add new customer and enter invalid phone number, it displays an error message which says 'Phone does match the pattern regex expression'. I have fixed this error message to display a more user friendly error message 'Please enter a valid phone number.'

Related Issues

Fixes #840: Add user-friendly validation messages for the Phone field on the customer page

Steps to Test

1. Go to Customer
2. Click on 'Add new Customer'
3. Enter invalid phone number or characters in phone field
4. It will display user friendly error message.

Screenshots (if applicable)

Before:

After:

Checklist

• I have tested these changes
• I have updated the relevant documentation
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the codebase
• My changes generate no new warnings or errors
• The title of my pull request is clear and descriptive