outlierdetection: Support health listener for ejection updates #13154

Job	Run time
vet-proto	30s
tests (vet, 1.22)	1m 59s
tests (extras, 1.23)	2m 52s
tests (tests, 1.23)	4m 7s
tests (tests, 1.23, -race)	5m 52s
tests (tests, 1.23, 386)	4m 55s
tests (tests, 1.23, arm64)	6m 25s
tests (tests, 1.22)	3m 54s
tests (tests, 1.23, -race, GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST=true)	5m 43s
	36m 17s

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