Revert "simpleperf: refactor code setting sample rate"

This reverts commit 4bca4fa192362199b97269812790dee1aa5110b9.

Reason for revert: Identified as culprit cl for test breakage b/305853586

Change-Id: Iba1170179b6f48a4a2f66e69c468b5f005b6f939
7 files changed