Merge "simpleperf: Remove unneeded Start() when using CapturedStderr." am: 8808586984

Original change: https://android-review.googlesource.com/c/platform/system/extras/+/2305212

Change-Id: I9eff02512c3dc55ded4639c7850522ce0fa3e9f3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>