Fix crash when removing fingerprint

Also fix a strings in fingerprint enrollment.

Bug: 21030545
Change-Id: I2d250b51a01f02bee014d4bc8e192d11199113e3
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 6e8fba4..0ffaf58 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -761,7 +761,7 @@
     <string name="security_settings_fingerprint_enroll_onboard_message">To use your fingerprint to unlock your screen or confirm purchases, you\u2019ll need to:</string>
     <!-- Introduction message shown in fingerprint enrollment dialog, first item to describe what
          the user needs to do. -->
-    <string name="security_settings_fingerprint_enroll_onboard_message_1">Setup your backup screen lock method</string>
+    <string name="security_settings_fingerprint_enroll_onboard_message_1">Set up your backup screen lock method</string>
     <!-- Introduction message shown in fingerprint enrollment dialog, second item to describe what
          the user needs to do. -->
     <string name="security_settings_fingerprint_enroll_onboard_message_2">Add your fingerprint</string>
@@ -791,7 +791,7 @@
     <!-- Message shown in fingerprint enrollment dialog once enrollment is completed -->
     <string name="security_settings_fingerprint_enroll_finish_message">Whenever you see this icon, you can use your fingerprint for identification or to authorize a purchase.</string>
     <!-- Button text to setup screen lock in onboard dialog [CHAR LIMIT=34] -->
-    <string name="security_settings_fingerprint_enroll_setup_screen_lock">Setup screen lock</string>
+    <string name="security_settings_fingerprint_enroll_setup_screen_lock">Set up screen lock</string>
     <!-- Button text to exit fingerprint wizard after everything is done [CHAR LIMIT=15] -->
     <string name="security_settings_fingerprint_enroll_done">Done</string>
     <!-- Dialog title for dialog which shows when user touches the icon on the screen, instead of the sensor at the back [CHAR LIMIT=45] -->
diff --git a/src/com/android/settings/fingerprint/FingerprintSettings.java b/src/com/android/settings/fingerprint/FingerprintSettings.java
index 5a69147..56f3ff6 100644
--- a/src/com/android/settings/fingerprint/FingerprintSettings.java
+++ b/src/com/android/settings/fingerprint/FingerprintSettings.java
@@ -259,9 +259,9 @@
 
         protected void removeFingerprintPreference(int fingerprintId) {
             String name = genKey(fingerprintId);
-            Preference prefToRemove = mManageCategory.findPreference(name);
+            Preference prefToRemove = findPreference(name);
             if (prefToRemove != null) {
-                if (!mManageCategory.removePreference(prefToRemove)) {
+                if (!getPreferenceScreen().removePreference(prefToRemove)) {
                     Log.w(TAG, "Failed to remove preference with key " + name);
                 }
             } else {