32Bit userland on aarch64 kernel sends wrong User Agent string

# General infomration
On arm32 bit userland using aarch64 kernel causes wrong User Agent string to Netflix, which causes key download to fail.
### Prerequisites
Install 32bit linux userland and use a 64bit linux kernel on Arm64 device

* [ ] Linux (x86/x64)
* [ ] OSX (x86/x64)
* [ ] Windows (x86/x64)
* [ x] Linux (ARM)
* [ ] Android

Attached is a patch that fixes the issue, and shouldnt cause any issues with any other platform. I had to give it a .txt extension due to upload rules.

[fix_arm32_on_aarch64.txt](https://github.com/asciidisco/plugin.video.netflix/files/2559007/fix_arm32_on_aarch64.txt)

Start by reviewing the attached fix_arm32_on_aarch64.txt patch and reproduce the stated setup: 32-bit Linux userland on an ARM64 device with an aarch64 kernel. Verify that the generated User-Agent sent to Netflix is correct and that key download succeeds without changing behavior on other listed platforms.

Written by the indexing model from the issue text.