sdkext module: set min_sdk_version to 30

Test: m com.android.sdkext
Bug: 171096530
Bug: 171330443
Change-Id: I0afbabc3673280670e89429e9dfa4cddf3bfbe1b
diff --git a/derive_sdk/Android.bp b/derive_sdk/Android.bp
index d170ba0..85672bd 100644
--- a/derive_sdk/Android.bp
+++ b/derive_sdk/Android.bp
@@ -22,7 +22,7 @@
         type: "lite",
         static: true,
     },
-    min_sdk_version: "current",
+    min_sdk_version: "30",
     shared_libs: ["liblog"],
     // static c++/libbase for smaller size
     stl: "c++_static",