Summary:
In the existing code, `pg_advisory_lock(int4, int4)` wrongly triggers the Release Advisory locks path instead of the Acquire.
```
pg_advisory_lock_int4(PG_FUNCTION_ARGS)
{
	...
        SET_LOCKTAG_INT32(tag, key1, key2);
	ReleaseYBAdvisoryLock(tag, YB_ADVISORY_LOCK_EXCLUSIVE);
	...
}
```

This diff fixes the issue by triggering the acquire advisory lock path in the above function.
Jira: DB-15046

Test Plan: ./yb_build.sh --java-test 'org.yb.pgsql.TestPgRegressIsolation#testPgRegress'

Reviewers: rthallam

Reviewed By: rthallam

Subscribers: ybase, yql

Differential Revision: https://phorge.dev.yugabyte.com/D41495