Add back compat config for NSD

Add back compat config for RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS, which was
lost when moving NsdManager to framework-connectivity-t.

This causes NsdManager to start mdnsresponder again when used by apps
with target SDK < 31.

The change also changes the compat ID used, to make sure it does not
conflict with the ID already in use in S and below, when the module is
installed on such a platform. This is the only ChangeId used by
framework-t.

Also add a CtsNetTestCasesMaxTargetSdk30 test to verify that behavior.

Bug: 235355681
Test: atest CtsNetTestCasesMaxTargetSdk30
Change-Id: I7ca6051d0a4ba5aff3e44bece2cbac22eb1be32d
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 4774866..1e8babf 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -36,6 +36,17 @@
     },
     // CTS tests that target older SDKs.
     {
+      "name": "CtsNetTestCasesMaxTargetSdk30",
+      "options": [
+        {
+          "exclude-annotation": "com.android.testutils.SkipPresubmit"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.RequiresDevice"
+        }
+      ]
+    },
+    {
       "name": "CtsNetTestCasesMaxTargetSdk31",
       "options": [
         {
@@ -103,6 +114,17 @@
       ]
     },
     {
+      "name": "CtsNetTestCasesMaxTargetSdk30[CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex]",
+      "options": [
+        {
+          "exclude-annotation": "com.android.testutils.SkipPresubmit"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.RequiresDevice"
+        }
+      ]
+    },
+    {
       "name": "CtsNetTestCasesMaxTargetSdk31[CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex]",
       "options": [
         {