Fix pendingIntent in SettingsSliceProvider could be Hijacked

A malicious app is able to obtain this pending intent.
It can then mutate all fields except for the action and
launch the intent. This can be used to launch any activity
with the ACTION_SETTINGS action.

So, we enfore assign the package name for this intent,
it only can launch the settings app.

Fix: 147355897
Test: a) Install the new settings apk, and it won't launch other screen.
(See details in bug)
b) Start the settings search, slice search results work as normal.

Change-Id: Ie954d8a4b7153d6a4cac40621f363b45185990f2