Skip telemetry when secrets binding is missing

[adamko147]

Issue

mta.yaml

resources:
   - name: dynatrace
     type: org.cloudfoundry.existing-service
     optional: true

as dynatrace is optional, in case it's not existing, the application should still start w/o telemetry

Suggested solution

Skip the telemetry setup if secrets binding is not found in VCAP_SERVCES env

[sjvans]

hi @adamko147

thanks for the input. our rationale: if @cap-js/telemetry is added, the user intends to use it. quietly skipping setup in case there is no
correct binding could mask setup errors. you, on the other hand, could set NO_TELEMETRY=true via mtaext for those deployment targets. hence, "won't fix".

best,
sebastian