Merge "scripts_reference.md: Add an information hierarchy: recorders and viewers" am: 9a043cf0e1 am: c1aefdae1e am: 0ab1bc47f8

Original change: https://android-review.googlesource.com/c/platform/system/extras/+/1839553

Change-Id: I6c73e977785f0017afafe696cfaebe900b05e361