Is there any way to disable the repeated animation in the notification bar, for app update downloads?
I don't have Android 9, but if some of the notifications are like on Android 8, then you can try the following:


Open Settings -> Apps &amp; Notifications. Click on "See all apps", then the 3-dot and select Show system apps.
Look for Download Manager, click on it. 
Click "App Notifications" or "Notifications", then disable "In progress"


Note: You may find 2 Download Manager. One of them will have the notifications' categories listed.