[Q] Lollipop's launcher on Kitkat??? topic

Hey guys, so I have Kitkat 4.4.4 installed on my Nexus 5 (for a lot of reasons, battery is much better, faster, and I love the Kitkat material design better than Lollipop).. But today, Play Store showed me an update for Google's application, so I updated it, and ever since I did that, I have Lollipop's launcher even though I'm using Kitkat o__o, so weird, do you have any information about this guys? (see screenshots).

Thanks :)

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