Don't depend on LockPatternUtils to get DevicePolicyManager

This fixes a crash where LockPatternUtils hasn't been set yet and
keyguard attempts to get the device policy for widgets.

This change breaks the dependency by getting a handle to DPM directly.

Bug:7109723

Change-Id: Iecae91474358821ebd30456648377253864c35cf

Author: Jim Miller

policy/src/com/android/internal/policy/impl/keyguard/KeyguardHostView.java

@@ -582,7 +582,9 @@ private void addWidget(int appId) {
     }
 
     private void maybePopulateWidgets() {
-        if (mLockPatternUtils.getDevicePolicyManager().getKeyguardWidgetsDisabled(null)
+        DevicePolicyManager dpm =
+                (DevicePolicyManager) mContext.getSystemService(Context.DEVICE_POLICY_SERVICE);
+        if (dpm != null && dpm.getKeyguardWidgetsDisabled(null)
                 != DevicePolicyManager.KEYGUARD_DISABLE_WIDGETS_NONE) {
             Log.v(TAG, "Keyguard widgets disabled because of device policy admin");
             return;