Move embedded notice file path above aapt rule generation

The embedded notice file generation for apps was moved below the aapt
rules, which meant the added asset path was ignored.  Move the code
to pick the notice file path selection back above the aapt rules,
and leave the code to generate the notice file rule where it is.

Bug: 236006463
Test: m NetworkStack ALWAYS_EMBED_NOTICES=true
Change-Id: I1421fb0dbcdb759281259abfae7bddc9aecdaa56
Merged-in: I1421fb0dbcdb759281259abfae7bddc9aecdaa56