Update SignalDrawable.

- Change SignalDrawable to render an SVG for the entire signal icon and
only draw by hand the X and the carrier change animation
- Changed carrier change animation to display a single dot at a time
instead of cutting out the entire row
- Removed unneeded methods due to single tone mobile signal icon
- Remove unused airplane mode state
- Remove unused CellTileView
- Add demo mode command inflate to inflate signal strengths
- Add GM2 cell signal drawables to the framework for 0-4 and 0-5 bars

TODO: should empty state be the same as 0 bar state?

Bug: 124107387
Test: visual
Change-Id: Ib5a0c3d89d35c1e21efb67e526c508aab100f2a0