Update git submodules

* Update external/perfetto from branch 'master'
  to 978a967b8001f3d0269d11a29d2bc5527604b37a
  - Merge "perfetto-ui: Fix stale heap profile viewing option"
  - perfetto-ui: Fix stale heap profile viewing option
    
    Bug:149824430
    Change-Id: Ia6e09e36df78772e58bb2045fd217603703b1ac6
    
1 file changed