Add public getters for compilation latency vars. am: 4e193ba163 am: e38fb05a1d

Original change: https://android-review.googlesource.com/c/platform/test/mlts/benchmark/+/1557568

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I09d0bf1f6d1a01829039cfb9a21106c758d030f7