Merge "profcollectd: add interface to wait for ETM after boot." am: d9d70c8fb6 am: bf0b895c05 am: 4e7acdc17a

Original change: https://android-review.googlesource.com/c/platform/system/extras/+/1944289

Change-Id: I0df11b90c1515a5e7d1483bc55b4a8179ba6a8e9