linux: fix build_apk.sh

tools/linux/build_apk.sh

@@ -9,6 +9,7 @@ if [ "$1" = "main" ]; then
     sdk_path="$(cat $HOME/.flutter_path)"
     echo "Using flutter sdk from: $sdk_path"
 
+    mkdir -p build/app/tmp
     flutter build apk --release --tree-shake-icons \
       --local-engine-src-path "$sdk_path/engine/src" \
       --local-engine=android_release --local-engine-host=host_release \
@@ -26,7 +27,7 @@ if [ "$1" = "main" ]; then
       --local-engine=android_release_x64 --local-engine-host=host_release \
       --split-per-abi \
       --target-platform android-x64
-    mv build/app/tmp/* build/app/outputs/flutter-apk
+    mv build/app/tmp/*.apk build/app/outputs/flutter-apk
   else
     echo "$HOME/.flutter_path not found!"
     exit 1