Fix fingerprint suggestion icon color.

- add tintable flag to the suggestion metadata so that it will be
displayed in correct tint color.

Change-Id: I29b6d3a8b7c47354d6022aea4d4f01986f5ce2b3
Fixes: 78655925
Test: visual

AndroidManifest.xml

@@ -1763,6 +1763,7 @@
                 android:resource="@string/suggested_fingerprint_lock_settings_title" />
             <meta-data android:name="com.android.settings.summary"
                 android:resource="@string/suggested_fingerprint_lock_settings_summary" />
+            <meta-data android:name="com.android.settings.icon_tintable" android:value="true" />
         </activity>
 
         <activity android:name=".password.ChooseLockGeneric$InternalActivity"