Fix defStyleRes fallback in obtainStyledAttributes

Existing code was not correctly retrieving the given defStyleRes style
if the lookup of defStyleAttr was failing. This would break the
rendering of components that do not define their styles in the current
theme.

Bug: 72598797
Test: Added regression test
Change-Id: I0c3535e7a0fd549a09d61dfba3d8e2393ed8ec4c