add support for 'expression' on outbound-channel-adapter [INT-1907]

[spring-operator]

Mark Fisher opened INT-1907 and commented

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Issue Links:

• outbound-channel-adapter should support the 'expression' attribute [INT-1906] #5892 outbound-channel-adapter should support the 'expression' attribute
  ("duplicates")

[spring-operator]

Oleg Zhurakousky commented

Duplicate to #5892