outlierdetection: Support health listener for ejection updates #13136

Job	Run time
vet-proto	34s
tests (vet, 1.22)	1m 32s
tests (extras, 1.23)	2m 45s
tests (tests, 1.23)	4m 7s
tests (tests, 1.23, -race)	5m 46s
tests (tests, 1.23, 386)	4m 43s
tests (tests, 1.23, arm64)	6m 41s
tests (tests, 1.22)	3m 37s
tests (tests, 1.23, -race, GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST=true)	5m 39s
	35m 24s

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