[mt-source] Fix ce-source missing the namespace

[lionelvillard]

Proposed Changes

• Propagate source namespace to the st adapter.

Release Note

Docs

[knative-prow-robot]

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This pull-request has been approved by: lionelvillard

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[codecov]

Codecov Report

Merging #361 (b7a42f5) into master (ffd2397) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #361   +/-   ##
=======================================
  Coverage   75.17%   75.18%           
=======================================
  Files         124      124           
  Lines        4705     4706    +1     
=======================================
+ Hits         3537     3538    +1     
  Misses        948      948           
  Partials      220      220           

Impacted Files	Coverage Δ
pkg/source/mtadapter/adapter.go	68.75% <100.00%> (+0.49%)	⬆️

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[steven0711dong]

/lgtm

[lionelvillard]

/test pull-knative-sandbox-eventing-kafka-integration-test-channel-consolidated