Moving FingerprintSettings to Kotlin

This change is the first of many, it will

1. Change java -> kotlin
2. Use the MVVM architecture
3. Be feature flagged

This change in particular is focused on transitions to and from various activities.

Enable feature via
adb shell setprop sys.fflag.override.settings_biometrics2_fingerprint true

Bug: 280862076
Test: atest FingerprintSettingsViewModelTest
Change-Id: I8eb5c30e6f2e92c256ae7c257a9d560439ba418f
diff --git a/Android.bp b/Android.bp
index f507f27..6fe7623 100644
--- a/Android.bp
+++ b/Android.bp
@@ -69,6 +69,7 @@
         "androidx.appcompat_appcompat",
         "androidx.cardview_cardview",
         "androidx.compose.runtime_runtime-livedata",
+        "androidx.activity_activity-ktx",
         "androidx.preference_preference",
         "androidx.recyclerview_recyclerview",
         "androidx.window_window",