chore: Rename otel classes #822

Job	Run time
filter	1m 11s
build(8) for gapic-generator-java	11m 1s
build (17)	13m 8s
dependency_analyzer_unit_test	1m 33s
build(25) except self-service clients	13m 6s
build(21) except self-service clients	13m 18s
build(8) except for gapic-generator-java	4m 40s
unmanaged_dependency_check	11m 25s
build (11)	14m 5s
showcase (25)	10m 25s
build(8) for showcase	10m 42s
showcase-clirr	5m 10s
showcase (21)	10m 53s
gapic-generator-java-bom	2m 34s
showcase (17)	10m 36s
showcase (11)	10m 42s
	2h 24m 29s

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