Resolve "Fix build process"

Closes #80 (closed)

.gitlab-ci.yml

@@ -33,7 +33,12 @@ android:build-debug:
     - flutter build apk --debug
     # prepare artifact
     - BASE_APK_FOLDER="build/app/outputs/flutter-apk"
-    - for APK in ${BASE_APK_FOLDER}/*.apk; do mv -v "${APK}" "$(echo "${APK}" | sed "s|\.apk|_${VERSION_CODE}.apk|")"; done
+    - >
+      if [ "$(find "${BASE_APK_FOLDER}" -name "*.apk")" != "" ]; then
+        for APK in ${BASE_APK_FOLDER}/*.apk; do
+          mv -v "${APK}" "$(echo "${APK}" | sed "s|\.apk|_${VERSION_CODE}.apk|")"
+        done
+      fi
     - find "${BASE_APK_FOLDER}" -name "*.apk" # where are my apk?
   artifacts:
     paths:
@@ -76,7 +81,12 @@ android:build-release:
         flutter build apk --release
       fi
     # prepare artifact
-    - for APK in ${BASE_APK_FOLDER}/*.apk; do mv -v "${APK}" "$(echo "${APK}" | sed "s|\.apk|_${VERSION_CODE}.apk|")"; done
+    - >
+      if [ "$(find "${BASE_APK_FOLDER}" -name "*.apk")" != "" ]; then
+        for APK in ${BASE_APK_FOLDER}/*.apk; do
+          mv -v "${APK}" "$(echo "${APK}" | sed "s|\.apk|_${VERSION_CODE}.apk|")"
+        done
+      fi
     - find "${BASE_APK_FOLDER}" -name "*.apk" # where are my apk?
   artifacts:
     paths: