bazel: add license to appropriate lib/ targets

This is to prepare for implementing genlicenses rule in bazel.

Change-Id: I60d79d5b53f9dd05c9f9ebfe6e6f658604c5a037

lib/jgit/org.eclipse.jgit.junit/BUILD

@@ -5,6 +5,7 @@ java_library(
   exports = ['@jgit_junit//jar'],
   runtime_deps = ['//lib/jgit/org.eclipse.jgit:jgit'],
   visibility = ['//visibility:public'],
+  data = ['//lib:LICENSE-DO_NOT_DISTRIBUTE'],
 )
 
 unsign_jars(