Fix lint error for those module used in mainline module

Bug: 187861723
Test: rebuild
Change-Id: I3a8c9e00f164d0f0dd381b188ecfd0c4a758a277
diff --git a/packages/SettingsLib/ActionBarShadow/Android.bp b/packages/SettingsLib/ActionBarShadow/Android.bp
index 800ab67..4a07d49 100644
--- a/packages/SettingsLib/ActionBarShadow/Android.bp
+++ b/packages/SettingsLib/ActionBarShadow/Android.bp
@@ -19,5 +19,5 @@
     ],
 
     sdk_version: "system_current",
-    min_sdk_version: "21",
+    min_sdk_version: "28",
 }