Fix force close of voicemail activity caused by screen rotation

Since VoicemailSettingsActivity does not handle horizontal/vertical
screen rotation properly, RuntimeException occurs when selecting contact
after screen rotation in "Choose a contact" view. Add configChanges
attributes in AndroidManifest.xml to fix the issue.

Bug: 32424108
Change-Id: I422328389dfd96444806a222b8ebbfc758daa477
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 61257f8..2acf1be 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -617,6 +617,7 @@
 
         <activity android:name="com.android.phone.settings.VoicemailSettingsActivity"
             android:label="@string/voicemail"
+            android:configChanges="orientation|screenSize|keyboardHidden"
             android:theme="@style/DialerSettingsLight">
             <intent-filter >
                 <!-- DO NOT RENAME. There are existing apps which use this string. -->