Web server exception occurs due to exceeding upload limit in case of uploading big files

1. Create simple custom files with "Alphanumeric" type of field (Custom Filed->Student->Select "Alphanumeric" type)
2. Navigate to the Import Multi value page and upload big 'tiff' file (just bigger then web server settings in my case 25M was enough)

Actual Result:

• Web server exception in browser
• Apache error log: PHP Warning: POST Content-Length of 119659761 bytes exceeds the limit of 8388608 bytes in Unknown on line 0, referer: http://127.0.0.1:8080/civicrm/import/custom?1

Expected Result:
Handling the size through javscript for the filed before uploading to the server

Note: I understand that this is very very rare case for end user so setting it to 'trivial'