Recognizing running "prebuilt" launcher and manually built platform

In scenarios like: atest NexusLauncherOutOfProcTests against the
platform built from command line, and Launcher from the platform, we are
not failing now, and @Stability treats it as a PLATFORM_POSTSUBMIT run.

Change-Id: Ia504216d238e58b2786f3749b737dfb95a2ede96