Improve reliablity of widget

The widget service held a reference to a single cursor, and
just called requery() on it when attempting update the data.  requery()
can fail, and if it does the cursor is invalid.

Now, use a CursorLoader to get updated cursors

Bug: 6819588
Bug: 5763272
Change-Id: Ic33d59560a24d66e5d0d586e7061b422eace70f9
2 files changed