Do not show soft keyboard when locked out

- Remove stateVisible for ConfirmLockPassword activity so that
  soft keyboard does not auto show up when the activity starts;
- Programatically show/hide soft keyboard when ConfirmLockPassword
  activity window gains focus;

Bug:20542149
Change-Id: I3faa20312d2d25752bd35b70dc8ed785e7687f0a
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 6fd534c..d8d1736 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -1407,7 +1407,7 @@
             android:theme="@style/Theme.ConfirmDeviceCredentials"/>
 
         <activity android:name="ConfirmLockPassword"
-            android:windowSoftInputMode="stateVisible|adjustResize"
+            android:windowSoftInputMode="adjustResize"
             android:theme="@style/Theme.ConfirmDeviceCredentials"/>
 
         <activity android:name=".fingerprint.FingerprintSettings" android:exported="false"/>
@@ -1424,7 +1424,7 @@
         <!-- Note this must not be exported since it returns the password in the intent -->
         <activity android:name="ConfirmLockPassword$InternalActivity"
             android:exported="false"
-            android:windowSoftInputMode="stateVisible|adjustResize"
+            android:windowSoftInputMode="adjustResize"
             android:theme="@style/Theme.ConfirmDeviceCredentials"/>
 
         <activity android:name="SetupChooseLockGeneric"