Iterating on data usage; tabs, scrolling, cycles.

Added ActionBar items to control complexity of data surfaced; checked
state causes tabs to be shown/hidden for "Mobile", "2G-3G", "4G", and
"Wi-Fi" network templates.  Loading historical stats and policy from
system services based on selected tab.

Change entire body under tabs to scroll, treating network options and
chart as ListView headers.  Teach chart sweep to disable intercept to
play with ListView, and draw sweep disabled as dashed line.  Hijacking
Preference views for toggles to offer consistency.  No policy updates
are persisted yet.

Based on available historical network stats and policy cycle reset day,
build list of user-selectable cycles.  Wired up chart to display cycle
data and reset inspection region to last week of available data.

Change-Id: Ia561578276fa23908b745fbc06a6ef828d9ccc2e