Issue 157: FIX:CWE-117,93 Log injection in PostgreSQL lambda_function.py

[seetamraju]

Issue # 157

Description of changes:
HIGH-Severity Security Vulnerability from AWS-Inspector.
CWE-117,93 Log injection

Analysis:

HIGH-Severity Security Vulnerability from AWS-Inspector.
CWE-117,93 Log injection
The PostgreSQL-related Lambdas have 3 "input" variables: arn token and step.
With no attempt to sanitize these inputs, these variables are logged using logger.

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*Even tho' these lambdas are NOT expected to be connected to APIGW, and are meant to be invoked via EventBridge-Cron, .. the AWS-Inspector, and other security-tools, will NEVER be able to confirm this, and so will continue to flag ALL Log-related vulnerabilities as high.

Since the FIX is trivial (add .encode() to EACH and EVERY logger-statement) and .. ..
.. Since the primary-code is UNTOUCHED (as in, we are NOT choosing to "fix" these 3 input-variables), ..
it is quite reasonable to conclude that there should be ZERO functional impact (that is, No new errors introduced).

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