Apexd: Add RAII wrapper for loopback device

Wrap release/free of loopback device in an RAII type.

Test: mmma system/apex/apexd
Test: adb push system/apex/apexd/apexd_testdata/test.apex /data/local/tmp && adb shell 'setenforce 0 ; cmd apexservice installPackage /data/local/tmp/test.apex && cmd apexservice mountPackage /data/apex/com.android.example.apex@1.apex'
Change-Id: Id74ebf2ac8b680f47cc6101c9b54c49e5581b0cf
1 file changed
tree: eee902e5278be2815c3924e20dec88e0e837b201
  1. apexd/
  2. apexer/
  3. testdata/
  4. Android.bp
  5. OWNERS
  6. PREUPLOAD.cfg