LWC Custom File Upload Component Along With New Record Creation

public with sharing class ContactController {
    @AuraEnabled
    public static string saveContact(Contact contactRec, string file, string fileName) {
        string contactId;
        try{
            Insert contactRec;
            contactId = contactRec.Id;
            base62File = EncodingUtil.urlDecode(base62File, 'UTF-8');      
            ContentVersion contentVersionRec = new ContentVersion();
            contentVersionRec.Title = fileName;
            contentVersionRec.PathOnClient = '/' + fileName;
            contentVersionRec.FirstPublishLocationId = contactRec.Id;
            contentVersionRec.VersionData = EncodingUtil.base64Decode(base62File);
            contentVersionRec.IsMajorVersion = true;
            Insert contentVersionRec;
        } catch(Exception ex){
            system.debug('Exception===>'+ex.getMessage());
        }
        return contactId;
    }    
}

import { LightningElement, track } from 'lwc';
import saveRecord from '@salesforce/apex/ContactController.saveContact';
import { NavigationMixin } from 'lightning/navigation';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
const MAX_FILE_SIZE = 100000000; //10mb
export default class NewRecordWithFileUpload extends NavigationMixin(LightningElement) {
    @track name;
    @track phone;
    @track email;
    @track description;
    uploadedFiles = []; file; fileContents; fileReader; content; fileName

    onNameChange(event) {
        this.name = event.detail.value;
    }
    onPhoneChange(event) {
        this.phone = event.detail.value;
    }
    onEmailChange(event) {
        this.email = event.detail.value;
    }
    onDescriptionChange(event) {
        this.description = event.detail.value;
    }
    onFileUpload(event) {
        if (event.target.files.length > 0) {
            this.uploadedFiles = event.target.files;
            this.fileName = event.target.files[0].name;
            this.file = this.uploadedFiles[0];
            if (this.file.size > this.MAX_FILE_SIZE) {
                alert("File Size Can not exceed" + MAX_FILE_SIZE);
            }
        }
    }

    saveContact() {
        this.fileReader = new FileReader();
        this.fileReader.onloadend = (() => {
            this.fileContents = this.fileReader.result;
            let base64 = 'base64,';
            this.content = this.fileContents.indexOf(base64) + base64.length;
            this.fileContents = this.fileContents.substring(this.content);
            this.saveRecord();
        });
        this.fileReader.readAsDataURL(this.file);
    }

    saveRecord() {
        var con = {
            'sobjectType': 'Contact',
            'LastName': this.name,
            'Email': this.email,
            'Phone': this.phone,
            'Description': this.description
        }
        saveRecord({
            contactRec: con,
            file: encodeURIComponent(this.fileContents),
            fileName: this.fileName
        })
            .then(conId => {
                if (conId) {
                    this.dispatchEvent(
                        new ShowToastEvent({
                            title: 'Success',
                            variant: 'success',
                            message: 'Contact Successfully created',
                        }),
                    );
                    this[NavigationMixin.Navigate]({
                        type: 'standard__recordPage',
                        attributes: {
                            recordId: conId,
                            objectApiName: 'Contact',
                            actionName: 'view'
                        },
                    });
                }
            }).catch(error => {
                console.log('error ', error);
            });
    }
}

<template>
    <div class="slds-box slds-theme_default">
        <div class="slds-m-around_medium">
            <lightning-input type="text" label="Name" onchange={onNameChange}></lightning-input>
            <lightning-input type="tel" label="Phone" onchange={onPhoneChange}></lightning-input>
            <lightning-input type="email" label="Email" onchange={onEmailChange}></lightning-input>
            <lightning-textarea name="input3" label="Description" onchange={onDescriptionChange}
                placeholder="type here..."></lightning-textarea>
            <lightning-input type="file" onchange={onFileUpload} required name="uploadFile" label="Upload File">
            </lightning-input>
        </div>
        <div>
            <center>
            <lightning-button label="Save" onclick={saveContact}>
            </lightning-button>
            </center>
        </div>
    </div>

</template>