Update git submodules

* Update external/protobuf from branch 'master'
  to bde6e2aac1ce740e44fe274b0fbc48fcf5cce9a7
  - Merge "Update cpe for vulnerability scanners"
  - Update cpe for vulnerability scanners
    
    Bug: http://b/201572953
    Change-Id: Ifbf3fa74207a5e6d23eba4806a9aec05cba44e95
    
1 file changed