Add experiment flag to control binder call stats.

For instance, to enabled detailed tracking locally.
adb shell settings put global binder_calls_stats detailed_tracking=true

Also adds the ability to turn off data collection completely and
changing the sampling interval. Uploading data through westworld can
re-use the same flag once implemented.

Test: Unit tested

Change-Id: I808c9902b8124ab643d9b197703d537da040ae3e