check for <application android:testOnly="true">
This adds a check for "testOnly" to the existing "debuggable" check, since
they are very similar. We should really be refactoring all the checks into
a more reasonable setup. Since "debuggable" and "testOnly" are both set in
the same place (<application>
in AndroidManifest.xml) and are both set
by the same process (running debug builds), I thought it would be OK to
include both in the same place. Plus it was a one-line change.
Thanks to @IzzySoft for flagging this IzzyOnDroid/repo#475 (closed)