Revert "Fix error checking in MemoryFile."

This reverts commit 2142c2cf6ffc0979fff7d0312fd6f90ca6c08a19.
Fix android.os.cts.MemoryFileTest#testLength

Change-Id: I4569ba7f35342ace20d5bb857da6e0d2d085ec8a
ActivityManager: Fix monkey tests

Change I30e38c6c27d339d55a8f9a0f4106185356a9b9a0 (adding ordered
broadcast prioritization) adds the assumption that every broadcast
generator has a full-fledged caller app, which isn't true for
monkey-created tests. Make sure the caller is a full app before
checking if it is AID_SYSTEM to avoid an NPE

Fixes com.android.cts.monkey.*

Change-Id: Ide0dd046c6c5eb10ab4acb504237b58cbbbd8cfa
Restore ProfileGroup notification override functionality

Also clean up a little.

JIRA: CYAN-3164
Change-Id: I9b71a225996315f517b59d2d6f4074175bbf2d64