Print settings polish

1. Added support for launching the top level print settings.

2. Updated some strings.

3. Removed the uninstall option for a print service.

4. Added search for the list of printers of a print service.

Change-Id: I9e175ba78b2d22b2bf90cf79153dc73327dfaff1

src/com/android/settings/Settings.java

@@ -960,4 +960,5 @@ public class Settings extends PreferenceActivity
     public static class UsbSettingsActivity extends Settings { /* empty */ }
     public static class TrustedCredentialsSettingsActivity extends Settings { /* empty */ }
     public static class PaymentSettingsActivity extends Settings { /* empty */ }
+    public static class PrintSettingsActivity extends Settings { /* empty */ }
 }