It seems to like this combination:
<changeSet author="Yong Wang" id="GRANT_TO_CS_APP_1" runOnChange="true">
<sqlFile
endDelimiter="\n"
path="SQL/grant_to_cs_app.sql"
splitStatements="true"
stripComments="true"
relativeToChangelogFile="true"
/>
</changeSet>
in grant_to_cs_app.sql file:
grant select,insert,update,delete on CS_EVENT_LOG to CS_APP
grant select,insert,update,delete on EVENT_CATEGORY to CS_APP