Update git submodules

* Update external/perfetto from branch 'master'
  to a43a405efbb3a52fd2cee05c19df1e0840a325a4
  - Merge "trace_processor: Add diff test for displayTimeUnit"
  - trace_processor: Add diff test for displayTimeUnit
    
    Change-Id: Ia23a010bc3c74b31fd5d42d206617ed54b22d925
1 file changed