Cache feature check for 1 minute for MethodCall instrumentation toggle

See merge request gitlab-org/gitlab-ce!15800

(cherry picked from commit 83998c0a)

53dc9e83 Cache feature check for 5 minutes for MethodCall instrumentation toggle
b503e6ff Implement simple in memory cache that expires after 5 minutes
6af84964 Set cache expire only once the cache is filled,
5904b033 Implemente measurement enabled cache using AtomicReference
408208bc Use AtomicFixNum to implement CAS isolated cache update.
ca176a9b move call_measurement_enabled? method to the bottom of the file
fd0a5168 use class variables instead of CONSTANTs
da19ce62 Expire feature flag cache after 1minute
51668d3e Use class variable and add rubocop exception
db9e5bf7 fix test case description