Update default activity animations

For T we will be using the cross fade animation proposed in go/t-activity-transitions (https://direct.googleplex.com/#/spec/241720001&247800001) - this is what we are implemented here

This animation only works properly if shell transitions are enabled as it uses the edgeExtension effect currently only implemented in shell

Test: atest FlickerTests
Bug: 202844659
Change-Id: Ibb863815b8a25f8d6ad0201203f7d550948f7158