Update git submodules

* Update external/icing from branch 'androidx-master-dev'
  to 5129c0360c3733dcfd036ea5aaf9190c80df623a
  - Merge remote-tracking branch 'aosp/upstream-master' into androidx-master-dev
    
    * aosp/upstream-master:
      Update Icing from upstream.
    
    Change-Id: I057ed60aa443b3632947538c3712252d80789e35
    
  - Update Icing from upstream.
    
    Change-Id: I662cd2f97794722eca9cc43b73549babed884be4