CI: Update to use SDK/NDK level 21 for Android on 32bit platforms

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

Author: kinnison

ci/docker/android/Dockerfile

@@ -1,6 +1,6 @@
 FROM rust-android
 
-ENV PATH=$PATH:/android/ndk/arm-14/bin:/android/ndk/arm64-21/bin:/android/ndk/x86-14/bin:/android/ndk/x86_64-21/bin \
+ENV PATH=$PATH:/android/ndk/arm-21/bin:/android/ndk/arm64-21/bin:/android/ndk/x86-21/bin:/android/ndk/x86_64-21/bin \
     CC_arm_linux_androideabi=arm-linux-androideabi-clang \
     CC_armv7_linux_androideabi=arm-linux-androideabi-clang \
     CC_aarch64_linux_android=aarch64-linux-android-clang \