*   Steps

       ->  Add Dependency
           ~   implementation "com.android.billingclient:billing-ktx:$billing_version"

       ->  Upload your App

       ->  Create and configure your products (On Console)
           ~   For each product, you need to provide a unique product ID, a title,
               a description, and pricing information.
           ~   Subscriptions have additional required information, such as selecting 
               whether it's an auto-renewing or prepaid renewal type for the base plan.

       1)  Initialize Billing Client
           ~   It is the main interface for communication between the Google Play 
               Billing Library and the rest of your app.
       2)  Start Connection
           ~   Connection Setup Disconnected
           ~   Connection Setup Finished
       3)  Query all available products detail by giving list of product_id.

       // Make Purchase
       4)  Query all available products detail by giving list of product_id.
       5)  Launch billing flow (bottomSheet)
       6)  Get Response, save it in SharedPreference or else