Support %s in product variable properties

Support using strings as product variable substitutions, and
add tests for printfIntoProperty.

Bug: 37035983
Test: varaible_test.go
Change-Id: I06cfadfb1d3fc81da72fb71323706df20426c8b7
Merged-In: I06cfadfb1d3fc81da72fb71323706df20426c8b7
(cherry picked from commit 7e0eaf15b9eec975e45f9e5a27294a0bf0ef9beb)

1 files changed, 1 insertions, 0 deletions

diff --git a/Android.bp b/Android.bp
index 640feb82..590521c6 100644
--- a/Android.bp
+++ b/Android.bp
@@ -71,6 +71,7 @@ bootstrap_go_package {
         "android/expand_test.go",
         "android/paths_test.go",
         "android/prebuilt_test.go",
+        "android/variable_test.go",
     ],
 }