feat: Client/StubSettings' getEndpoint() returns the resolved endpoint #5825

Job	Run time
build (11)	1m 15s
build(8) except for gapic-generator-java	1m 7s
build (17)	1m 10s
build(21) except self-service clients	1m 8s
compatibility	1m 30s
build(8) for gapic-generator-java	9m 21s
lint	33s
gapic-generator-java-bom	2m 1s
showcase (11)	3m 57s
showcase (17)	3m 56s
showcase-clirr	2m 58s
showcase-native	8m 36s
unmanaged_dependency_check	3m 37s
	41m 9s

Provide feedback