Allow QS tiles to open dialogs

Add a TYPE_QS_DIALOG window type, that is in the same layer as
apps and dialogs and such.  It is guarded by having a token
that is granted by SysUI after a click has occured.  If the
app shows a dialog before listening finishes (QS closes) then
the token will stay granted until the tile is removed by the
user, otherwise the token will be removed immediately to avoid
later dialogs.

Also fix a couple tiny TileService issues:
 - Stop/Start listening reversed
 - Fix javadoc referencing wrong action

Change-Id: Iedcdd5fd9a2af2b33eb7f6f17bb0e6c997879876