Add min SDK to auxiliary overlay package

Without this the package receive the same min SDK as the branch it is
built on. This means that a package build in master (UDC) cannot be
installed on a T build and the test will fail.

Bug: 210089326
Test: atest SafetyCenterConfigTests
Change-Id: I11d512ace2b68c10a7913e9348de9d4081b59f3e
diff --git a/SafetyCenter/Config/tests/overlay/Android.bp b/SafetyCenter/Config/tests/overlay/Android.bp
index 06bea53..72b31db 100644
--- a/SafetyCenter/Config/tests/overlay/Android.bp
+++ b/SafetyCenter/Config/tests/overlay/Android.bp
@@ -21,6 +21,7 @@
 android_test_helper_app {
     name: "SafetyCenterConfigTestsOverlay",
     sdk_version: "current",
+    min_sdk_version: "30",
     test_suites: [
         "general-tests",
         "mts-permission",