Update Validation of MediaAlly.php Trait

[cw-alihyder]

It was giving an error on $request->file I just make it to validate whether the given parameter is actually an instance of the upload file or not.

[unicodeveloper]

@cw-alihyder What error was it giving?

[cw-alihyder]

it's not letting the user go to next keep throwing the Exception even if it's a file Instance.

[unicodeveloper]

So how does your PR fix it? @cw-alihyder

[cw-alihyder]

now my PR fixes this by validating whether the param is actually an instance of UploadedFile or not. If it will not instance of UploadedFile it will throw an exception. On the other hand, file_exist doesn't work with the UploadFile instance.