Add maxTargetSdk restriction to unused APIs.

These are APIs that have @UnsupportedAppUsage but for which we don't
have any evidence of them currently being used, so should be safe to
remove from the unsupported list.

Bug: 170729553
Test: Treehugger
Change-Id: I4c8fd0006f950de9955242e93968fb0996ceb372

rs/java/android/renderscript/Font.java

@@ -19,6 +19,7 @@ package android.renderscript;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.res.AssetManager;
 import android.content.res.Resources;
+import android.os.Build;
 import android.os.Environment;
 
 import java.io.File;
@@ -237,7 +238,7 @@ public class Font extends BaseObj {
      *
      * Returns default font if no match could be found.
      */
-    @UnsupportedAppUsage
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
     static public Font create(RenderScript rs, Resources res, String familyName, Style fontStyle, float pointSize) {
         String fileName = getFontFileName(familyName, fontStyle);
         String fontPath = Environment.getRootDirectory().getAbsolutePath();