[native pos] Remove workaround of isNative flag passed to SqlToRowExpressionTranslator

[vermapratyush]

isNative flag passed to SqlToRowExpressionTranslator from SqlFunctionUtils is hard coded to false https://github.com/vermapratyush/presto/blob/d5eed561c31e21cb0b6cfa5f94038d9d4f2b4b89/presto-main/src/main/java/com/facebook/presto/sql/relational/SqlFunctionUtils.java#L111
https://github.com/prestodb/presto/blob/d5eed561c31e21cb0b6cfa5f94038d9d4f2b4b89/presto-main/src/main/java/com/facebook/presto/sql/relational/SqlFunctionUtils.java#L111

Ideally, this should be derived from session value, hard coding this to false does not break any flow since we always disable inline sql function for native:
https://github.com/prestodb/presto/blob/master/presto-native-execution/src/test/java/com/facebook/presto/nativeworker/NativeQueryRunnerUtils.java#L42

[vermapratyush]

For SqlFunctionUtils,

the solution would be to add the isNative flag to the connector session and pass it through when we create the connector session.