Added dampening logic to caluclate the distance to
overscroll.
Updated StretchEffect to support independent
maximum stretch amounts for the x/y axis
Removed debugging parameters to configure
stretch distance since they are no longer
used. Removed hidden API calls to configure
stretch distance in ScrollView/HorizontalScrollView
Bug: 179047472
Test: re-ran EdgeEffectTests
Change-Id: I4698669273d364695a21c2cce00ec2cfec41b2cc
--Ported SKSL based stretch shader from OpenGL prototype
--Hooked up the stretch APIs in RenderNode to the stretch
shader.
--Updated RenderNode layer logic to promote the RenderNode to
a layer if there is a stretch to be applied to it in order
to feed the layer as input to the stretch shader
Bug: 179047472
Test: builds + sample overscroll stretches + updated CTS test
Change-Id: I744ff70099fe251ce07f23d067bf13444a468c08