Final adjustments to privacy metrics:

- remove unnecessary lock - after statsd added locks for each puller, there
is no need to create additional lock for sampling rate estimation
- adjust sampling target value for AppOps atom based on Beta1 results
- adjust sampling ratio for Dangerous Permission state atom

Test: statds_testdrive 10069, 10075, atest UidAtomTests#testAppOps
--iterations=20, atest UidAtomTests#testDangerousPermissionState
--iterations=20, atest UidAtomTests#testDangerousPermissionStateSampled
--iterations=20
Bug: 143519689
Change-Id: I05fec5f602c7e1c5ba38749147c04aec79da2a46