Revert "Revert "Propagate proguard rules from LOCAL_STATIC_ANDROID_LIBRARIES""

This reverts commit 30d6869f.

Fixes an issue with the original change where proguard files without
newlines at the end of the file would get merged with the next file.
Most of the time the next file started with a comment, which worked
fine, but sometimes it was a syntax error.

Bug: 72969557
Test: m
Test: build on an internal tree that failed last time
Change-Id: I66f13ae80ee0f96b456e526bfbfc2cdcf82c3f3a