Rollout edit monitor to 10% users

Simplified the logic in whether to enable edit monitor by passing the
rollout percentage directly instead of reading from a env variable as
now we do not rely on any env var to control the rollout precentage.

Test: atest edit_monitor_utils_test
Bug: 365617369
Change-Id: Ia04d5737dafe2c9715a02f84eb5d75ba6119ceb4