do not run proguard in `ant debug` builds, it breaks the tests

The whole Android ant build system was built around the assumption that proguard is only run on the release builds. Running proguard on the debug builds breaks the test instrumentation, which does something like insert the emma methods into each class. In theory, this could be fixed, but I think its a bad idea to heavily customize the ant build system since its basically deprecated in favor of gradle.

Here's the proguard warning message: [proguard] Warning: can't find referenced class com.vladium.emma.rt.RT

Instead, there is probably a way to test the release build. For example, in the Jenkins build, I added ant clean release, then it installs the APK, and runs the "monkey tester" on it.