Delete hiddenapi-blacklist.txt file

The file is empty and not used, and its presence confuses people.
Remove it.

Bug: 64382372
Test: make
Change-Id: I8646a78b96d81dd38e5c58460d354430babd9d53
diff --git a/config/hiddenapi-blacklist.txt b/config/hiddenapi-blacklist.txt
deleted file mode 100644
index e69de29..0000000
--- a/config/hiddenapi-blacklist.txt
+++ /dev/null