Propagate traces from local observations to downstream spans

## Expected Behavior Local observations should propagate the context to downstream spans. ## Actual Behavior Local observation create a span but do not propagate context to downstream spans. ## Steps to Reproduce the Problem <!-- How can a maintainer reproduce this issue (be detailed) --> ## Release Note <!-- How should the fix for this issue be communicated in our release notes? It can be populated later. --> <!-- Keep it as a single line. Examples: --> <!-- RELEASE NOTE: **ADD** New feature in Dapr. --> <!-- RELEASE NOTE: **FIX** Bug in runtime. --> <!-- RELEASE NOTE: **UPDATE** Runtime dependency. --> RELEASE NOTE: