ksoap2: compile against min_sdk_version = 30

Bug: 171330443
Test: compiles
Change-Id: Id8204353eae760a9f33fa76ad46947cbe7ed1d34
diff --git a/Android.bp b/Android.bp
index 9f9ce89..19deb85 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,5 +1,6 @@
 java_library {
     name: "ksoap2",
-    sdk_version: "system_30",
+    sdk_version: "system_current",
+    min_sdk_version: "30",
     srcs: ["**/*.java"],
 }