Remove Multidex usages

[MGaetan89]

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• I have read how to contribute to this project
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Contributor checklist

• I am following the Code Style Guidelines
• I have tested my contribution on these devices:

• Google Pixel 9 Pro XL (emulator), Android 15

• My contribution is fully baked and ready to be merged as is
• I ensure that all the open issues my contribution fixes are mentioned in the commit message of my first commit using the Fixes #1234 syntax

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Description

Since the min SDK is at least 21, it is no longer necessary to use the Multidex library.

See the following for more info: https://developer.android.com/build/multidex#mdex-on-l

[greyson-signal]

Ah, thank you! This will go out in 7.18.x