Move ReceiveKeyActivity back to themed dialog activity.

AndroidManifest.xml

@@ -151,6 +151,7 @@
 
     <activity android:name=".ReceiveKeyActivity" 
               android:label="@string/AndroidManifest__complete_key_exchange"
+              android:theme="@style/TextSecure.Light.Dialog"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
     
     <activity android:name=".ApplicationPreferencesActivity"

src/org/thoughtcrime/securesms/ReceiveKeyActivity.java

@@ -16,6 +16,7 @@
  */
 package org.thoughtcrime.securesms;
 
+import android.app.Activity;
 import android.app.ProgressDialog;
 import android.content.Intent;
 import android.os.AsyncTask;
@@ -44,7 +45,7 @@ import org.thoughtcrime.securesms.util.MemoryCleaner;
  * @author Moxie Marlinspike
  */
 
-public class ReceiveKeyActivity extends PassphraseRequiredSherlockActivity {
+public class ReceiveKeyActivity extends Activity {
 
   private TextView descriptionText;