[Cronet] Make CtsNetHttpTestCases installable on older devices

This fixes a pre-existing failure on APCT.

Bug: 283927908
Test: atest CtsNetHttpTestCases
Change-Id: If341c11dd3e18be10f6c5e9984d1da304e655d23
diff --git a/Cronet/tests/cts/Android.bp b/Cronet/tests/cts/Android.bp
index 44b3364..1e0adef 100644
--- a/Cronet/tests/cts/Android.bp
+++ b/Cronet/tests/cts/Android.bp
@@ -53,7 +53,9 @@
     defaults: [
         "cts_defaults",
     ],
+    enforce_default_target_sdk_version: true,
     sdk_version: "test_current",
+    min_sdk_version: "30",
     static_libs: ["CtsNetHttpTestsLib"],
     // Tag this as a cts test artifact
     test_suites: [