SP-986 - MongoDB Output Step throws ArrayIndexOutOfBounds when input field is missing

checkstyle applied
SP-986 - MongoDB Output Step throws ArrayIndexOutOfBounds when input field is missing.

PDI-9989 fix to 5.0 version
SP-986 - MongoDB Output Step throws ArrayIndexOutOfBounds when input field is missing

junit checkstyle applied
SP-986 - MongoDB Output Step throws ArrayIndexOutOfBounds when input field is missing.

junit tests added