Allow license build rule name to be overridden.

We need this in order to use cargo_embargo in crates with multiple
versions (or we need to have an Android.bp patch for the deprecated version of every crate).

Not sure this is the best way to do it, but it works.

Bug: http://b/339424309
Test: treehugger
Change-Id: I624792c9fd7eb31622952a98aa6b4130a4356a30
1 file changed