Back out "fix(json): Ensure input is parsed as json for json extract functions" (facebookincubator#12514)

Summary:
Pull Request resolved: facebookincubator#12514

Temporarily backing out this change as it is failing some internal unit tests.

Reviewed By: kgpai

Differential Revision: D70498020

fbshipit-source-id: 1137958fb0c87e4e53bc78bb12ea16c75124aeff

Author: Bikramjeet Vig

velox/docs/functions/presto/json.rst

@@ -156,8 +156,6 @@ JSON Functions
         SELECT json_extract(json, '$.store.book');
 
     Current implementation supports limited subset of JSONPath syntax.
-    If ``json`` is a varchar then it is expected to conform to `RFC 7159`_ and will be converted to its canonical
-    format before extraction.
 
     .. _JSONPath: http://goessner.net/articles/JsonPath/
 
@@ -171,10 +169,6 @@ JSON Functions
         SELECT json_extract_scalar('[1, 2, 3]', '$[2]');
         SELECT json_extract_scalar(json, '$.store.book[0].author');
 
-    Current implementation supports limited subset of JSONPath syntax.
-    If ``json`` is a varchar then it is expected to conform to `RFC 7159`_ and will be converted to its canonical
-    format before extraction.
-
     .. _JSONPath: http://goessner.net/articles/JsonPath/
 
 .. function:: json_format(json) -> varchar
@@ -189,9 +183,8 @@ JSON Functions
 
 .. function:: json_parse(varchar) -> json
 
-    Expects a JSON text conforming to `RFC 7159`_, and returns the JSON value (in its canonical form) deserialized
-    from the JSON text. The JSON value can be a JSON object, a JSON array, a JSON string, a JSON number, ``true``,
-    ``false`` or ``null``::
+    expects a JSON text conforming to `RFC 7159`_, and returns the JSON value deserialized from the JSON text.
+    The JSON value can be a JSON object, a JSON array, a JSON string, a JSON number, ``true``, ``false`` or ``null``::
 
         SELECT json_parse('[1, 2, 3]'); -- JSON '[1,2,3]'
         SELECT json_parse('"abc"'); -- JSON '"abc"'