Settings Fragment Migration (Build pass app)

This patch focused on fixing compile errors and some runtime errors.

Test: We can't test it now. But we will have an integration test later.
Bug: 110259478
Change-Id: I16c471ddcd0fa1460c665b7f74d86fcace5ee67b
diff --git a/proguard.flags b/proguard.flags
index 7592370..298058d 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -6,7 +6,7 @@
 -keepattributes Exceptions
 
 # Keep all Fragments in this package, which are used by reflection.
--keep public class com.android.settings.** extends android.app.Fragment
+-keep public class com.android.settings.** extends androidx.fragment.app.Fragment
 
 # Keep all preference controllers needed by slice and DashboardFragment.
 -keep class * extends com.android.settings.core.BasePreferenceController {