I was able to install the Play Store version (side loaded) 5.2.13 armv7a on my Nexus Player today and its working fine in HD.
Took my Player out to connect to my PC monitor to use while WFH in covid and noticed 'AmazonSyncAccount.....' under Accounts section in Settings. Tried to Install the latest version apk and it Works!
Helpful for anyone still using this old Player.
It installs and I can log in, but when I click to watch something I get:
Something went wrong
Please try again later. For more help, go to PrimeVideo.com/videohelp