Revert "Revert "[TimeStats] Add callback for global stats""

This reverts commit de64c56f39b03f4908200d1ed2fdc9561f86fe2a.

Reason for revert: Rolling forward with fix

Test: adb shell cmd stats pull-source 10062
Change-Id: I981b12a1c5e69aad0c0d3a409d8b90b3399401f4
7 files changed