Mass clean up: don't cast class when not needed.

Bug: none
Test: rebuild
Change-Id: Ie3f58a3d5ae99ade28a33dcac80c18de90d4d5b2

src/com/android/settings/security/ChangeScreenLockPreferenceController.java

@@ -79,7 +79,7 @@ public class ChangeScreenLockPreferenceController extends AbstractPreferenceCont
     @Override
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
-        mPreference = (RestrictedPreference) screen.findPreference(getPreferenceKey());
+        mPreference = screen.findPreference(getPreferenceKey());
     }
 
     @Override

src/com/android/settings/security/LockUnificationPreferenceController.java

@@ -77,7 +77,7 @@ public class LockUnificationPreferenceController extends AbstractPreferenceContr
     @Override
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
-        mUnifyProfile = (RestrictedSwitchPreference) screen.findPreference(KEY_UNIFICATION);
+        mUnifyProfile = screen.findPreference(KEY_UNIFICATION);
     }
 
     public LockUnificationPreferenceController(Context context, SecuritySettings host) {

src/com/android/settings/security/OwnerInfoPreferenceController.java

@@ -61,7 +61,7 @@ public class OwnerInfoPreferenceController extends AbstractPreferenceController
 
     @Override
     public void displayPreference(PreferenceScreen screen) {
-        mOwnerInfoPref  = (RestrictedPreference) screen.findPreference(KEY_OWNER_INFO);
+        mOwnerInfoPref  = screen.findPreference(KEY_OWNER_INFO);
     }
 
     @Override

src/com/android/settings/security/ResetCredentialsPreferenceController.java

@@ -52,7 +52,7 @@ public class ResetCredentialsPreferenceController extends RestrictedEncryptionPr
     @Override
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
-        mPreference = (RestrictedPreference) screen.findPreference(getPreferenceKey());
+        mPreference = screen.findPreference(getPreferenceKey());
     }
 
     @Override

src/com/android/settings/security/trustagent/TrustAgentListPreferenceController.java

@@ -91,7 +91,7 @@ public class TrustAgentListPreferenceController extends AbstractPreferenceContro
     @Override
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
-        mSecurityCategory = (PreferenceCategory) screen.findPreference(PREF_KEY_SECURITY_CATEGORY);
+        mSecurityCategory = screen.findPreference(PREF_KEY_SECURITY_CATEGORY);
         updateTrustAgents();
     }