AbstractMapper does not pass 0 values throughout if statement

[andriusvo]

Summary
We want to set a index on an integer property of our class. The value can be any integer - 0, 1, 2 .. whatever. But then reindex command is executed, AbstractMapper function setDataValue is called and value is not going into 172 line if($value), because it is false then if(0). It should be if(null !== $value)

Steps to reproduce

1. Set an index on any integer property there value can be 0.
2. Run reindex command
3. Value is not inserted into oro_search_index_integer DB table.

Actual Result Value is not inserted into oro_search_index_integer DB table.

Expected Result
Value should be insrted into oro_search_index_integer DB table.

Actual code line - https://github.com/oroinc/platform/blob/3360ced4494c60dce997aa7e8fd8798dd74811b8/src/Oro/Bundle/SearchBundle/Engine/AbstractMapper.php#L115

[anyt]

Thank you for the detailed report, @SSMellow! Internal ticket id #BAP-20091.