[build] check any raw SWIG wrapper files generated by SWIG (#309)

To avoid generating raw wrapper files, we perform checks during the
build process to prevent this.

android/build-commissioner-libs.sh

@@ -67,6 +67,14 @@ cd ../
 
 rm -rf "$BUILD_DIR"/libs && mkdir -p "$BUILD_DIR"/libs
 
+## Check JNI contains any raw swig wrapper files
+
+if find "$BUILD_DIR"/src/java/io/openthread/commissioner -name "SWIGTYPE_*" -print -quit | grep -q .; then
+  echo "***********  please check SWIG file \"commissioner.i\"  ***********"
+  echo "Failed to create JAR library due to raw swig wrapper files under $BUILD_DIR/src/java/io/openthread/commissioner"
+  exit -1
+fi
+
 ## Create JAR library
 javac -source 8 -target 8 "$BUILD_DIR"/src/java/io/openthread/commissioner/*.java