security image tests do not finish

[Jamie Strandboge]

I tried running the security tests (eg, http://ci.ubuntu.com/smokeng/utopic/touch/mako/32:20140515.2:20140513.2/8044/security/) on an x86 emulator.

Steps to reproduce (for more details about running the security tests, see README.image_tests in qa-regression-testing):
1. bzr branch lp:qa-regression-testing

2. cd ./qa-regression-testing

3. create and start the emulator. Eg:
$ sudo XDG_CACHE_HOME=$HOME/emulator ubuntu-emulator create --channel=ubuntu-touch/utopic-proposed --arch=i386 --revision=32 test_x86
$ ubuntu-emulator run --scale=0.5 test_x86

4. push the tests to the emulator:
$ adb push ./tests /tmp/tests

5. Run the tests:
$ adb shell /tmp/tests/image/run_tests.sh

At some point the emulator locks up and is unresponsive (can't adb shell into it or anything).

This may be due to LP: #1294373 since if I do this before running the tests, they finish:
$ adb shell
# sudo -H -u phablet -i
$ stop unity8 # this takes a while