Apexd: Add database duplicates check

Add a check for duplicate loop and dm devices. As we are correctly
tearing them down now, this becomes important.

Add tests.

Bug: 116593293
Bug: 129347238
Test: atest apex_database_test
Change-Id: I7bf34420cec3808181a8baad0bd725e5c7e685ae
2 files changed
tree: 0dac2971553d8b0a9a5146d910aaa7240c3a2856
  1. apexd/
  2. apexer/
  3. proto/
  4. shim/
  5. tests/
  6. OWNERS
  7. PREUPLOAD.cfg