test: do not show unnecessary BatcherImplTest logging (#2519) #5453

Job	Run time
build (11)	12m 23s
build (17)	12m 10s
build(21) except self-service clients	11m 18s
build(8) except for gapic-generator-java	3m 24s
build(8) for gapic-generator-java	9m 43s
compatibility	1m 38s
lint	29s
showcase (11)	3m 56s
showcase (17)	4m 13s
gapic-generator-java-bom	1m 47s
showcase-clirr	0s
showcase-native	7m 38s
unmanaged_dependency_check	3m 31s
	1h 12m 10s

Provide feedback