Install cbindgen in android build script

Temporary fix to address maybenot.h (checked in) sometimes needing to
be re-generated due to how `make` looks at last-modifications while
git neither stores nor consistently sets modification metadata on
file checkout.

build-apk.sh

@@ -77,6 +77,11 @@ mkdir -p "app/build/extraAssets"
 mkdir -p "app/build/extraJni"
 popd
 
+# Temporary fix to address maybenot.h (checked in) sometimes needing to be
+# re-generated due to how `make` looks at last-modifications while git neither
+# stores nor consistently sets modification metadata on file checkout.
+cargo install --force cbindgen
+
 for ARCHITECTURE in ${ARCHITECTURES:-aarch64 armv7 x86_64 i686}; do
     case "$ARCHITECTURE" in
         "x86_64")