Align insrumentation TLS config with collector

[pavolloffay]

Description:

This PR aligns instrumentation TLS options with collector config:

    receivers:
      otlp:
        protocols:
          grpc:
            endpoint: 0.0.0.0:4317
            tls:
              cert_file: /otelcol-certs/tls.crt
              key_file: /otelcol-certs/tls.key
          http:
            endpoint: 0.0.0.0:4318
            tls:
              cert_file: /otelcol-certs/tls.crt
              key_file: /otelcol-certs/tls.key

Link to tracking Issue(s):

• Resolves: #issue-number

Testing:

Documentation: