Bump actions/cache from 2.1.6 to 2.1.7
Bump actions/cache from 2.1.6 to 2.1.7

Fixes #5788

RELNOTES=n/a
PiperOrigin-RevId: 414547550

google/guava,google/guava,mosoft521/guava,mosoft521/guava,google/guava,mosoft521/guava