Add new facility for apps to declared their preferred intents.

This is an extension from the existing data/etc/perferred-apps
facility.  Now applications pre-installed on the system image
can declare which intents they would like to be considered the
preferred app for.  When the system firsts initializes, or the
application settings are reset, these are used to configured
the current preferred app settings appropriately.

You use this with a new <preferred> tag under your activity,
which indicates which intents you would like to be the preferred
handler for.  The syntax for this is written much like an
intent filter, however semantically it is not really an intent
filter and so has some important differences:

- You can not use globbing patterns (for SSPs or paths).
- You can use only one action (if you use more than one it
  will only use the first one, so be careful).

Semantically what this is actually used for is a template
from which to generate a set of Intent objects, which are used
to probe the current environment in order to see if there are
multiple activities that can handle the Intent and, if so,
generate a new preferred setting for that pointing to your app.

As an example, here is how the preferred tag might be written
for the Maps application:

            <preferred>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data android:scheme="http" />
                <data android:scheme="https" />
                <data android:host="maps.google.com" />
                <data android:path="/" />
                <data android:pathPrefix="/maps" />
            </preferred>
            <preferred>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data android:scheme="geo" />
            </preferred>

From this, we generate the following set of potential Intents
to be matched, all with ACTION_VIEW, CATEGORY_DEFAULT+CATEGORY_BROWSABLE:

Change-Id: I7fd42aec8b6109c7dd20012529662362f1b7437a
http://maps.google.com/
http://maps.google.com/maps
https://maps.google.com/
https://maps.google.com/maps
geo: