Fix many of the ANRs introduced by scheduling classes.

We weren't bumping the oom_adj of processes receiving a registered broadcast.  Previously
this wasn't a problem, because those processes are allowed to have their oom_adj
managed by whatever else is in them and if the registered receiver goes away no problem.
But now this is also controlling the scheduling class, so we need to bump them up.

This is probably good anyway, since the developer has the same assurance of their process
not being killing in the middle of registered receivers like it had always been for
manifest receivers.

Also fixed a small issue where we were not recomputing the oom_adh after finished with
a broadcast.