Introduce dialogs for precise editing of network policy warning/limit
values, triggered by click on sweep labels. Show up to 999MB before
rounding to GB, and round to nearest 5MB value when dragging. Partial
D-pad navigation around chart controls. Fix jumping when relayout
during drag, and fix sweep overlap bug.
When restricting data without limited networks, show dialog help to
guide user towards network limit. When reloading chart data, try
restoring to nearest cycle.
Bug: 5289641, 5111701, 5226078
Change-Id: Ic59dee6496c480a64dc56f8534acf4d81b50bca7
