Fix -Wreorder-init-list

frameworks/base/services/incremental/IncrementalService.cpp:2004:29: warning: ISO C++ requires field designators to be specified in declaration order; field 'signature' will be initialized after field 'metadata' [-Wreorder-init-list]
 2004 |                 .metadata = {targetLibPath.c_str(), (IncFsSize)targetLibPath.size()},
      |                 ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
frameworks/base/services/incremental/IncrementalService.cpp:2002:30: note: previous initialization for field 'signature' is here
 2002 |                 .signature = {},
      |                              ^~

Test: presubmit
Change-Id: I7c71ed46f36f30f3bff947e513b6a021d1c61b8c