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/mts/Android.bp b/Tethering/tests/mts/Android.bp
index edb6356..221771f 100644
--- a/Tethering/tests/mts/Android.bp
+++ b/Tethering/tests/mts/Android.bp
@@ -19,7 +19,10 @@
 android_test {
     // This tests for functionality that is not required for devices that
     // don't use Tethering mainline module.
-    name: "MtsTetheringTest",
+    name: "MtsTetheringTestLatestSdk",
+
+    min_sdk_version: "30",
+    target_sdk_version: "30",
 
     libs: [
         "android.test.base",
diff --git a/Tethering/tests/mts/AndroidTest.xml b/Tethering/tests/mts/AndroidTest.xml
index 80788df..4edd544 100644
--- a/Tethering/tests/mts/AndroidTest.xml
+++ b/Tethering/tests/mts/AndroidTest.xml
@@ -24,7 +24,7 @@
     <option name="config-descriptor:metadata" key="parameter" value="secondary_user" />
     <target_preparer class="com.android.tradefed.targetprep.suite.SuiteApkInstaller">
         <option name="cleanup-apks" value="true" />
-        <option name="test-file-name" value="MtsTetheringTest.apk" />
+        <option name="test-file-name" value="MtsTetheringTestLatestSdk.apk" />
     </target_preparer>
     <test class="com.android.tradefed.testtype.AndroidJUnitTest" >
         <option name="package" value="android.tethering.mts" />