bug: CheckUserExist component is causing mobile failure

[anantakumarghosh]

Description
In CheckUserExist, some texts are in plane instead of being in any CoreTypography component, which is causing failure for mobile.

Addtionally, on typing anything on input field, mobile app crashing because of improper validation handling for mobile.
emailOrPhone

[anantakumarghosh]

Temporarily removed validation for emailorphone validation

[anantakumarghosh]

Handing over to @techoneel and @sumanta-m

[anantakumarghosh]

currently changed changes needs to be merged.