Update transition dumping structure

- We used to keep track of the transition proto and update it as we went along the transition pipeline and would then only add it to the trace buffer when the transition finished or was aborted.
- We now dump partial transition protos as we get the information moving through the pipeline, which are then joined up together using transition id when the trace is processed.
- This way of tracing is more compatible with Perfetto tracing and simplifies any logic required to keep track of the transition protos.

Bug: 277181336
Test: Collect transition trace and load into Winscope
Change-Id: I7d0004f2f0aa233a760cfc31d1aef5dcb39b9c43