Drop clearkey also on Android

We ship libclearkey.so on Andorid, whereas we explicitly remove it on desktop (f4f0ae02, it has its own commit!).

It's another 33kB we can get back for free.

Archive:  tor-browser-qa-android-x86_64-tbb-nightly.2026.01.18.apk
Zip file size: 115723758 bytes, number of entries: 2131
-rw-r--r--  6.3 unx    81000 bx    33783 defN 26-Jan-12 17:08 lib/x86_64/libclearkey.so