Fix issue #10688644: Java crash in com.android.phone:

java.lang.SecurityException: Operation not allowed

There was a situation I wasn't taking into account -- components
declared by the system has a special ability to run in the processes
of other uids.  This means that if that code loaded into another
process tries to do anything needing an app op verification, it will
fail, because it will say it is calling as the system package name but
it is not actually coming from the system uid.

To fix this, we add a new Context.getOpPackageName() to go along-side
getBasePackageName().  This is a special call for use by all app ops
verification, which will be initialized with either the base package
name, the actual package name, or now the default package name of the
process if we are creating a context for system code being loaded into
a non-system process.

I had to update all of the code doing app ops checks to switch to this
method to get the calling package name.

Also improve the security exception throw to have a more descriptive
error message.

Change-Id: Ic04f77b3938585b02fccabbc12d2f0dc62b9ef25