Add sdk_version property to imported jars

Test: m checkbuild
Change-Id: I83dd6ad157c7a5918747ce8c9be05c1e1e22d710
diff --git a/java/androidmk.go b/java/androidmk.go
index e7f79d2..c61b7e5 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -76,6 +76,7 @@
 			func(w io.Writer, outputFile android.Path) {
 				fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE := true")
 				fmt.Fprintln(w, "LOCAL_SOONG_HEADER_JAR :=", prebuilt.combinedClasspathFile.String())
+				fmt.Fprintln(w, "LOCAL_SDK_VERSION :=", prebuilt.properties.Sdk_version)
 			},
 		},
 	}