[colocated] Truncate on colocated table is not removing records properly

[Arjun-yb]

Truncate table is not removing records properly with colocated DB/table
DB Version: 2.11.2.0-b54
Steps:

1. Create colocated database and table.
2. Load some data
3. Create unique index.
4. Truncate table
5. Read data from table
6. Load same data again and observe the behaviour.

ex:

yugabyte=# CREATE DATABASE colocated_db colocated = true;
CREATE DATABASE
yugabyte=# \c colocated_db;
You are now connected to database "colocated_db" as user "yugabyte".
colocated_db=# CREATE TABLE col_temp_tbl (h INT PRIMARY KEY) WITH (colocated = true);
CREATE TABLE
colocated_db=# INSERT INTO col_temp_tbl VALUES (1), (2), (3);
INSERT 0 3
colocated_db=# create unique index on col_temp_tbl(h);
CREATE INDEX
colocated_db=# truncate col_temp_tbl;
TRUNCATE TABLE
colocated_db=# SELECT * from col_temp_tbl;
 h 
---
(0 rows)

colocated_db=# INSERT INTO col_temp_tbl VALUES (1), (2), (3);
ERROR:  duplicate key value violates unique constraint "col_temp_tbl_h_idx"

[frozenspider]

Closing as a duplicate of #10912