Handle includes for generated headers

For generated headers, Soong introduces the package to the includes (and
re-exports as necessary).

Test: bp2build.sh
Change-Id: Iea9cda859ddaa3e5393f0f4533c15fc60222c408
diff --git a/bp2build/cc_binary_conversion_test.go b/bp2build/cc_binary_conversion_test.go
index 2446850..b46248f 100644
--- a/bp2build/cc_binary_conversion_test.go
+++ b/bp2build/cc_binary_conversion_test.go
@@ -303,6 +303,7 @@
         ":not_explicitly_exported_whole_static_dep",
         ":whole_static_dep",
     ]`,
+				"local_includes": `["."]`,
 			},
 			},
 		},