Remove uses of UsesNativeCallProxy and UsesGeckoThreadProxy, now that
they are not needed.
Remove cases where we had to invoke a call in a proxy, because the call
is now specified to be invoked directly in the WrapForJNI annotation,
without the need to go through the proxy.
For SmsManager and AlarmReceiver, we no longer need to manually dispatch
everything to the Gecko thread because that's now handled automatically.
