Migrate Settings to androidx.

Test: make Settings
Bug: 76692459
Change-Id: I941dea40562170649bf056e675cc32e5163c0e39
diff --git a/proguard.flags b/proguard.flags
index 36de97b..7592370 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -45,9 +45,9 @@
 }
 
 # Keep annotated classes or class members.
--keep @android.support.annotation.Keep class *
+-keep @androidx.annotation.Keep class *
 -keepclassmembers class * {
-    @android.support.annotation.Keep *;
+    @androidx.annotation.Keep *;
 }
 
 # Keep specific fields used via reflection.
@@ -55,4 +55,4 @@
     public static ** SEARCH_INDEX_DATA_PROVIDER;
     public static ** SUMMARY_PROVIDER_FACTORY;
 }
--keep class android.support.v4.app.CoreComponentFactory
+-keep class androidx.core.app.CoreComponentFactory