[M138-LTS] SkEventTracer::SetInstance always leaks

M138-LTS conflicts:
  src/utils/SkEventTracer.cpp: a simple conflict involving header
  inclusion that got fixed.

Bug: b/487750530
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1183796
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Florin Malita <fmalita@google.com>
(cherry picked from commit a7665f11022cb12dc33a6f427e58052e4e99ebb8)

Change-Id: I122b8696469e3a97669f5cb53a2e642a73466cf7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1202796
Reviewed-by: Michael Ludwig <michaelludwig@google.com>