Add insecure flag for tls to otlp endpoint in collectors-config and SDKs

[emdneto]

As a best practice, I think we should explicitly include the insecure flag in the TLS configuration for both otel-collector and recipe samples, even though some are set as default.

    tls:
      insecure: false

For example: here and here

[joaopgrassi]

Makes sense!