Eliminate link-tree for aapt2 link
Eliminate link-tree for aapt2 link

Summary:
Instead of creating a link-tree for .flata files during aapt2 link, pass the flata files directly into aapt using -R aapt2-args.txt. This is less complex, and very slightly faster.

This also changes the aapt2 link execution to pass in all input files with relative paths (this wasn't easy earlier, because we had to cd to the link-tree directory).

Reviewed By: asp2insp

shipit-source-id: 9d977f902e

zpao/buck,kageiit/buck,JoelMarcey/buck,JoelMarcey/buck,facebook/buck,nguyentruongtho/buck,JoelMarcey/buck,zpao/buck,Addepar/buck,Addepar/buck,zpao/buck,facebook/buck,kageiit/buck,JoelMarcey/buck,nguyentruongtho/buck,Addepar/buck,Addepar/buck,Addepar/buck,nguyentruongtho/buck,Addepar/buck,Addepar/buck,JoelMarcey/buck,nguyentruongtho/buck,kageiit/buck,kageiit/buck,Addepar/buck,facebook/buck,kageiit/buck,zpao/buck,Addepar/buck,JoelMarcey/buck,Addepar/buck,nguyentruongtho/buck,zpao/buck,facebook/buck,facebook/buck,JoelMarcey/buck,JoelMarcey/buck,nguyentruongtho/buck,JoelMarcey/buck,Addepar/buck,JoelMarcey/buck,JoelMarcey/buck,zpao/buck,JoelMarcey/buck,Addepar/buck,Addepar/buck,kageiit/buck,facebook/buck,facebook/buck,kageiit/buck,JoelMarcey/buck,nguyentruongtho/buck,zpao/buck