Dump target sdk version for ConnectivityCoverageTests into 31

Address TODO since 31 is available now

Test: atest ConnectivityCoverageTests
Change-Id: I40618bd4a3d8b314bf0ed7c75cd15f48439c5520
diff --git a/tests/common/Android.bp b/tests/common/Android.bp
index f47f6b0..c533dab 100644
--- a/tests/common/Android.bp
+++ b/tests/common/Android.bp
@@ -64,8 +64,7 @@
     name: "ConnectivityCoverageTests",
     // Tethering started on SDK 30
     min_sdk_version: "30",
-    // TODO: change to 31 as soon as it is available
-    target_sdk_version: "30",
+    target_sdk_version: "31",
     test_suites: ["general-tests", "mts-tethering"],
     defaults: [
         "framework-connectivity-test-defaults",