deps: Upgrade google-http-client to v2.1.1 #3687

Job	Run time
filter	1m 12s
downstream-compatibility (java-bigtable)	9m 16s
downstream-compatibility (java-firestore)	4m 20s
downstream-compatibility (spring-cloud-gcp)	11m 20s
downstream-compatibility (java-pubsub)	3m 57s
conditional-required-check	2s
	30m 7s

Provide feedback