Due to critical security issue in the software (CVE-2020-3143) all the older software loads have been deferred and are no longer available.
The old Android software has been unsupported for a couple of years now, so it's not recommended that you go back to that.
If you absolutely need to, you are best to contact the Cisco TAC who should be able to help under your service contract and provide you with the required software.
Last resort - if you do a web search for the dx80.ce8.2.0-syn213B.rel.pkg file you are after you can find it available on a number of non-Cisco download sites - I wouldn't recommend this as there is no certainty that these files are safe and/or will work, or if these sites are full of viruses and trojans, etc which may be worse. You are on your own to determine whether you want to go down this path or not.
Wayne
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