chore: update GH Action templates to use gapic-libraries-bom version #1449

Job	Run time
filter	59s
build(8) for showcase	9m 51s
build(21) except self-service clients	13m 26s
build(8) for gapic-generator-java	11m 30s
build(25) except self-service clients	13m 29s
build(8) except for gapic-generator-java	4m 17s
build (17)	14m 34s
unmanaged_dependency_check	9m 15s
build (11)	14m 49s
dependency_analyzer_unit_test	1m 22s
gapic-generator-java-bom	2m 21s
showcase-clirr	5m 10s
showcase (21)	13m 34s
showcase (17)	13m 8s
showcase (25)	29m 47s
showcase (11)	13m 15s
	2h 50m 47s

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