Restore final canvas state after deferred flush

bug:8450062

- Fixes overdraw indication with DeferredDisplayList
- Fixes drawHardwareLayer called after flush

Additionally changes drawLayer to pass its paint to native via setLayerPaint

Wrap flush in save/restore so that reordering doesn't affect final
transform

Change-Id: I08befa42c28500da6387699eefd4be28aedf9f4c