android: require NDK r26b

This fixes `no member named 'invocable' in namespace 'std'`

android/build.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env -S python3 -u
 
 import os, os.path
+import shutil
 import sys, subprocess
 
 if len(sys.argv) < 4:
@@ -60,8 +61,11 @@ configure_args += [
     '-Dandroid_ndk=' + ndk_path,
     '-Dandroid_abi=' + android_abi,
     '-Dandroid_strip=' + toolchain.strip,
+    '-Dopenssl:asm=disabled'
 ]
 
 from build.meson import configure as run_meson
 run_meson(toolchain, mpd_path, '.', configure_args)
-subprocess.check_call(['/usr/bin/ninja'], env=toolchain.env)
+
+ninja = shutil.which("ninja")
+subprocess.check_call([ninja], env=toolchain.env)

doc/user.rst

@@ -197,7 +197,7 @@ Compiling for Android
 You need:
 
 * Android SDK (sdk platform 29, build tools 29.0.3)
-* `Android NDK r25b <https://developer.android.com/ndk/downloads>`_
+* `Android NDK r26b <https://developer.android.com/ndk/downloads>`_
 * `Meson 0.56.0 <http://mesonbuild.com/>`__ and `Ninja
   <https://ninja-build.org/>`__
 * cmake
@@ -207,6 +207,7 @@ You need:
 * zip
 * libtool
 * rsvg-convert 
+* python 3.9+
 
 Just like with the native build, unpack the :program:`MPD` source
 tarball and change into the directory.  Then, instead of