Add GlowPieEffect (first pass)

Add GlowPieEffect that rotates two pie slices with glow + base glow.

The effect will be drawn behind the target view, so it's not masked to
be shown as a border.

Bug: 335315940
Flag: NA. currently not used anywhere.
Test: GlowPieEffectTest
Change-Id: Ic0f9c5887695a6697fa05f5e3092fb97802886d0
4 files changed