apexd: make exception-free

Do not use APIs which can throw exceptions.
- add and use WalkDir() helper instead of directory_iterator
- use noexcept version of is_block_file()

Bug: 124662897
Test: atest apexservice_test
Test: adb shell pm list packages --apex-only (after restart)
Change-Id: Ie42ba763903521c43e21381e3ae9871cd71120fd
2 files changed
tree: e2b81c1a59910855617227bf1e9b3e0717c6463f
  1. apexd/
  2. apexer/
  3. proto/
  4. shim/
  5. tests/
  6. CleanSpec.mk
  7. OWNERS
  8. PREUPLOAD.cfg