Android - Different Internet connectivity errors for both Sign in & Register screens

Description:
When the user tries to sign in without the internet (Empty Fields), an invalid email error occurs. In contrast, when the user tries to register without the internet (Empty Fields), an Internet connectivity error occurs.

Note: The logic behind this is that when there is no internet and we try to sign in with empty fields, the server first checks the validation of the fields and then the connection. According to this logic, the Sign-in behavior is correct

Steps to Reproduce:

• Install the openedX app
• Load the app
• Go to the Register screen
• Switch off the internet
• Tap on the Create account button with empty fields
• Notice the user gets an internet connectivity error

Expected Behavior:
The Behavior for both Register & Sign in should be the same

Start by reproducing the offline, empty-field submission on the Register and Sign in screens, then trace their validation and connectivity handling. Done means both screens show the same behavior for this scenario, with the relevant validation covered or verified by the existing app tests if available.