Add check_all_apis option for header ABI checker

This commit adds a header ABI checker option to check all APIs that can
be found.  Without this option, the checker by default only checks the
class/struct/enum that are directly or indirectly referred by one of the
exported symbols.  With `check_all_apis: true,`, the checker will check
all class/struct/enum.

Bug: 141709599
Test: Add `header_abi_checker: { check_all_apis: true, }` to a library
      and see breakage if I change some enum.
Change-Id: I61f90e07b60a6752fc6be4398420c1ad1291102f