android build: switch from "cryptography" to "pycryptodomex"

We had been using an ancient version of "cryptography" so far in our p4a fork,
however it is not compatible with OpenSSL 3.0. (Previously we were building it with OpenSSL 1.1)

Bumping "cryptography" is difficult, as building new versions of it from source requires a full rust toolchain.

Instead, this commit switches to "pycryptodomex", as a replacement, which is much easier to build from source.

contrib/android/buildozer_qml.spec

@@ -76,7 +76,7 @@ requirements =
     plyer,
     libffi,
     libsecp256k1,
-    cryptography,
+    pycryptodomex,
     pyqt6sip,
     pyqt6,
     libzbar

contrib/android/p4a_recipes/pycryptodomex/__init__.py

@@ -0,0 +1,15 @@
+from pythonforandroid.recipe import PythonRecipe
+
+
+assert PythonRecipe.depends == ['python3']
+assert PythonRecipe.python_depends == []
+
+
+class PycryptodomexRecipe(PythonRecipe):
+    version = "3.23.0"
+    sha512sum = "951cebaad2e19b9f9d04fe85c73ab1ff8b515069c1e0e8e3cd6845ec9ccd5ef3e5737259e0934ed4a6536e289dee6aabac58e1c822a5a6393e86b482c60afc89"
+    url = "https://github.com/Legrandin/pycryptodome/archive/v{version}x.tar.gz"
+    depends = ["setuptools", "cffi"]
+
+
+recipe = PycryptodomexRecipe()