Test mts against last stable api level

Create *LatestSdk variant build target which have target sdk specify
to allow test apk install to released platform.

Bug: 182211575
Test: test S MtsTetheringTest in R device
Change-Id: I4d5c5e8c3d74993a67380e0211da31884cbf8792
diff --git a/Tethering/tests/unit/Android.bp b/Tethering/tests/unit/Android.bp
index d469b37..b4b3977 100644
--- a/Tethering/tests/unit/Android.bp
+++ b/Tethering/tests/unit/Android.bp
@@ -36,13 +36,13 @@
         "framework-tethering.impl",
     ],
     visibility: [
-        "//cts/tests/tests/tethering",
         "//packages/modules/Connectivity/tests/cts/tethering",
     ],
 }
 
 java_defaults {
     name: "TetheringTestsDefaults",
+    min_sdk_version: "30",
     srcs: [
         "src/**/*.java",
         "src/**/*.kt",
@@ -81,10 +81,10 @@
 // unit test code. It is not currently used by the tests themselves because all the build
 // configuration needed by the tests is in the TetheringTestsDefaults rule.
 android_library {
-    name: "TetheringTestsLib",
+    name: "TetheringTestsLatestSdkLib",
     defaults: ["TetheringTestsDefaults"],
+    target_sdk_version: "30",
     visibility: [
-        "//frameworks/base/packages/Tethering/tests/integration",
         "//packages/modules/Connectivity/Tethering/tests/integration",
     ]
 }