WM tracing: use perfetto protos

Adapt the WindowManager tracing code to use the protos in
external/perfetto (SOT), instead of those in frameworks/base.

The protos in frameworks/base are a duplicate of the SOT that
still exist to ease the transition to perfetto, but eventually
they are going to be deleted.

Flag: EXEMPT mechanical refactoring
Test: presubmit
Bug: 323165543
Change-Id: I1c5f4fc316d71c9b3b4a9c14feff690bbee254fd