Add UiBench jank and macrobench tests for saveLayer performance

Create 2 jank tests and 1 macrobench that measure saveLayer
performance:
- Fling a ListView, which has a vertical fading edge.
- Draw a canvas with 20 saveLayer/restore interleaved with other
drawText and drawRect ops.

Test: built and ran UiBench jank and macrobench tests.
Change-Id: I5a50feb7431d597c92c7a49031505d41f397d175