Build a new FooterPreference UI.

- Create a new layout for footer prefs.
- Create a new FooterPreference type to use the layout
- Create a Mixin to create and add the pref to screen
- Create a new lifecycle observer type to invoke mixin at right time
- Switch SettingsPreferenceFragment to use footer mixin.
- Switch FingerprintSettings to use the new footer pref.

Bug: 33579394
Test: RunSettingsRoboTests
Change-Id: I548ac39a0d120196a7ffed09b4f98bd9a80bae90

tests/robotests/src/com/android/settings/widget/RingProgressBarTest.java

@@ -16,21 +16,21 @@
 
 package com.android.settings.widget;
 
-import static junit.framework.Assert.assertEquals;
-
 import android.content.Context;
 import android.view.View.MeasureSpec;
 
+import com.android.settings.SettingsRobolectricTestRunner;
 import com.android.settings.TestConfig;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.robolectric.RobolectricTestRunner;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
 
-@RunWith(RobolectricTestRunner.class)
+import static junit.framework.Assert.assertEquals;
+
+@RunWith(SettingsRobolectricTestRunner.class)
 @Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
 public class RingProgressBarTest {