This is the first step, including:
1. Bring the group tag back by reverting.
2. If there is no group tag, then treat all the paths as a single group.
Make sure our test cases covering both cases.
At the same time, fix one tiny UI bug in the test.
TODO:
1. Move the rotation to the group tag.
2. Add translation/scale to the group tag.
3. Convert the group into a tree hierarchy.
This reverts commit 404211630ba3bb865109434aba4433e7541b39d3.
Conflicts:
graphics/java/android/graphics/drawable/VectorDrawable.java
Change-Id: Ife65bb6a7fc85f9947124b8e356cd5b82119796a
6d9c422de5