Set draw drop shadow for vector pointer icons when sprite is set.

Drop shadow was not being retained when reloading pointers, like when
the display size changes.

Bug: 305193969
Test: Manual
Flag: ACONFIG com.android.systemui.enable_vector_cursors STAGING
Change-Id: Ic6c80166df0d64ca5709aac7ca401f442564698d
3 files changed