Unified headers were removed in NDK 16

Author: gnzlbg

ci/android-install-ndk.sh

@@ -29,7 +29,6 @@ case "$1" in
 esac;
 
 android-ndk-r19c/build/tools/make_standalone_toolchain.py \
-        --unified-headers \
         --install-dir "/android/ndk-${1}" \
         --arch "${arch}" \
         --api 26