Suppress deprecation warnings in LegacyTypeTrackerTest.

This saves dozens of warnings every time FrameworkNetTests is
compiled. There is nothing we can do about those warnings because
LegacyTypeTracker's reason for existence is to power deprecated
APIs.

Test: m FrameworksNetTests
Change-Id: I4d65b0aade493e12b56a94247efbf9d1ad7bb4b9

tests/net/java/com/android/server/LegacyTypeTrackerTest.kt

@@ -14,6 +14,11 @@
  * limitations under the License.
  */
 
+// Don't warn about deprecated types anywhere in this test, because LegacyTypeTracker's very reason
+// for existence is to power deprecated APIs. The annotation has to apply to the whole file because
+// otherwise warnings will be generated by the imports of deprecated constants like TYPE_xxx.
+@file:Suppress("DEPRECATION")
+
 package com.android.server
 
 import android.net.ConnectivityManager.TYPE_ETHERNET